I9 7900x review: Intel Core i9 7900X review: the best around, but the worst time to buy a high-end CPU

Intel Core i9 7900X review: the best around, but the worst time to buy a high-end CPU

We’re going to look back on last year as a genuine WTF?! moment in CPU tech. And this inaugural i9 processor, the Intel Core i9 7900X, is one of the bits of silicon we’ll hold up to exemplify all the weirdness.

There’s a whole lot of serious silicon out there right now, so check out our pick of the best CPUs for gaming so you know where to spend your upgrade cash.

The Core i9 7900X is a ten-core $969(£780) processor. Last year, that would have made it the tippy top of Intel’s high-end desktop (HEDT) tech tree, but this year it’s the bottom rung of the new Core i9 range, and sits in the middle of the entire X-series CPU stack.

Yeah, a ~$1,000 CPU as a mid-ranger. Told you times were weird.

As much as Intel are keen to keep on trotting out the old‘none of this has anything to do with AMD, honest’ line we know that, without increased AMD Threadripper-shaped competition from the red team, we wouldn’t be looking at a new range of processors topping out at a ludicrous 18 cores.

But none of that has happened yet. The Core i9 7980XE is a $2,000 chip, after a few hastily scribbled drawings on the back of an engineer’s napkin left in the Intel canteen. AMD’s 16-core offerings though offer a far more tantalising prospect for anyone looking for a high core-count CPU.

So, with Threadripper around

, is there anything to be gained from trying to get your mitts on a Core i9 7900X right now?

Click on the jump links below to get to your chosen section double-quick.

  • Intel Core i9 7900X specs

  • Intel Core i9 7900X benchmarks

  • Intel Core i9 7900X performance

  • Intel Core i9 7900X verdict

Intel Core i9 7900X architecture

The i9 7900X is only the second decacore CPU Intel have produced, with last year’s Broadwell-E Core i7 6950X being the first to land in a consumer desktop. It’s built on the updated 14nm CPU architecture Intel first introduced with the Skylake range of mainstream processors at the end of 2015. Since then, we’ve had the subsequent Kaby Lake update, with the likes of the Core i7 7700K and i5 7600K. Intel are also bringing that same architecture to bear on their HEDT range with the Kaby Lake-X Core i7 7740X and Core i5 7640X chips.

In real terms, there’s not a lot of difference between the earlier Skylake and Kaby Lake updates, so it makes sense for Intel to bring the HEDT chips up to date with their current chip architecture for the first time. Traditionally, the HEDT range has been a couple of generations behind the mainstream market. On the surface, there’s not a lot between those designs and the older 14nm Broadwell-E one either, but there are a few key underlying differences which Intel have brought to bare with the new Skylake-X architecture.

The main one being Intel’s introduction of a new mesh architecture, brought in from the Xeon server side of the business, to replace the previous ring bus CPU design. It’s essentially a new set of interconnects to sit inside the CPU, specifically designed to cater to the demands of chips with many more cores than they’ve previously been specced out for.

It’s roughly analogous to AMD’s Infinity Fabric, which connects the two quad-core Zen modules in their octacore Ryzen CPUs. Y’know, the ‘glue’ that Intel have previously mocked the red team for using to connect the Zen modules in their AMD Threadripper design.

The old ring bus was starting to look a little out of touch with Broadwell-E’s high-core-count chips, with it providing an increasingly circuitous route for data shifting between core components. The new mesh system has more of a cross die grid structure, which Intel claims provides higher bandwidth and lower latency – while also operating at a lower frequency and therefore lower voltage – than the ring design.

Intel have switched around the cache hierarchy on the Skylake-X chips too. They’ve decreased the L3, last-level cache (LLC), on a per-core basis, but are providing more low-latency L2, mid-level cache (MLC). That manifests itself as a reduction from 2.5MB L3 cache/core with Broadwell-E down to 1.375MB/core with Skylake-X, but with an increase from 256KB/core of MLC up to a full 1MB/core. The shared LLC is great for distributing data across cores, but by enlarging the amount of responsive MLC cache dedicated to each core, Intel claim they are able to boost core performance too.

In memory news, the platform’s quad-channel DDR4 support has been increased from Broadwell-E’s 2,400MHz max to a 2,666MHz standard with the Skylake-X chips. Well, all except the bottom-end hexcore i7 7800X, which has the old specification.

Intel have also implemented a new version of Turbo Boost Max. With the Skylake-X CPUs, the chips are able to identify the two fastest cores within their processor package and utilise those specifically for less thread-intensive workloads – that ought to be good for game loads as they should be able to max out the speed on specific cores doing the majority of the gaming grunt work. The Broadwell-E chips, by comparison, were only able to identify the quickest single core and prioritise that.

We also get a whole new socket with the new X-series. The X299 chipset comes with the LGA 2066 socket housing, you guessed it, 2,066 pins for you to accidentally jam your thumbs into and b0rk your board. Good times.

Intel Core i9 7900X specs

That’s the broad overview, but, in terms of specifics, the Core i9 7900X is a ten-core CPU making full use of Intel’s HyperThreading technology to deliver a hefty 20 threads of processing goodness to the user. That, in itself, is not massively exciting, given that we had our first taste of such a multicore CPU last year, but the speed at which Intel have got the first Core i9 running is impressive.

The first Intel decacore, the Core i7 6950X, had a base clock of just 3GHz and a Turbo frequency of 3.5GHz. Once in a blue moon, if the wind is blowing in the right direction, and you’ve completed the necessary incantations in perfectly pronounced Esperanto, you might be able to get the single-core frequency up to 4GHz. The Core i9 7900X has a base clock of 3.3GHz, which doesn’t make it seem a huge amount quicker than its forebear, but the big difference is that Turbo speed of 4.3GHz.

That’s not just a single-core boost clock either. In our MSI X299 Gaming M7 ACK test board, the 7900X runs with all cores at 4.3GHz whenever it’s being pushed by CPU-intensive applications. Intel have also given it a Turbo Boost Max frequency of 4.5GHz, but the gods were obviously displeased with us as we never saw hide nor hair of such speed in stock configuration. I fear for this year’s harvest… we must consult the oracle.

Because of the rejigged Skylake-X cache hierarchy, the 7900X has a slightly smaller total cache than the 6950X’s 25MB. The 7900X, by contrast, has 10MB of L2 and 13.75MB of L3 cache for a 23.75MB total. Y’know, just in case you couldn’t do the maths by yourself.

It’s also got a few more PCIe lanes too, rocking a full 44 PCIe 3.0 lanes direct from the CPU itself as opposed to the 40 of the 6950X. There’s a big step down from the Core i9 7900X to the eight-core i7 7820X, which has just 28 lanes by comparison. If you’re wanting to build yourself a mighty multi-GPU machine then the 7900X looks like it’s got the goods, though the upcoming AMD Threadripper chips will all have 64 PCIe 3.0 lanes…

Intel Core i9 7900X benchmarks

Intel Core i9 7900X performance

Guess what, it’s quick. Actually the i9 7900X is the quickest processor I’ve ever tested. Intel have launched the fastest desktop processor ever and it’s not even going to be the most powerful X-series CPU in the range. Golly. That makes the Core i9 7900X a tough act to follow, not just for AMD’s Threadripper, but also for the rest of Intel’s HEDT range.

It’s got unprecedented multi-threaded performance, easily topping last year’s inaugural ten-core 6950X, making AMD’s octacore Ryzen 7 1800X look every inch the half-price option. The i9 7900X, thanks to that impressively high all-core Turbo clockspeed, also has some serious single-threaded chops too.

But that doesn’t always translate into a big performance lead in-game. With the Hitman and Total War benchmarks the Intel CPU displays its single-threaded dominance over the current top AMD part, but that disappears with the Vulkan version of Doom and even in GTA V. That said, benchmark performance of Grand Theft Auto has fluctuated since our Ryzen testing, as you can also see with the legacy frame rates of our old 6800K sample.

The biggest gaming performance difference, however, was in the Civilization VI AI benchmark. The average turn time for the AI to make its strategic moves was nearly six seconds faster with the 7900X compared with the eight-core AMD chip.

But that slight overall gaming performance lead is not going to justify spending twice the money to get the extra two cores the Intel i9 offers over the Ryzen CPU. Us gamers just aren’t getting enough extra out of the X-series platform to make it worth serious consideration.

That’s true even when considering the extra overclocking headroom the Intel chips have. I was able to get the 7900X to run with an all-core clockspeed of 4.7GHz without any trouble, delivering the highest Cinebench score I’ve ever seen on our test bench. But that comes at a definite thermal and power cost.

When pushed above 4.5GHz the temperature of the 7900X becomes more than our all-in-one liquid chip-chiller could handle, even with both the pump and fans running as fast as they could go. At 4.7GHz, the CPU package regularly hit the 100°C mark, at which point the processor starts to throttle individual cores to bring the temperature back down. Anything over 4.7GHz and the throttled clockspeed severely tanks, sometimes to below 4GHz.

Intel Core i9 7900X verdict

There has never been a worse time to buy a new high-end CPU. While it’s safe to say that right now the Core i9 7900X is the fastest desktop processor around, that’s in no way an invitation for you to think about buying one.

AMD have confirmed their cheaper 16-core Ryzen Threadripper chip will outperform this first ever Core i9 CPU at launch. Even as I write this, Intel have quietly announced the 2.9GHz base clock of the 12-core i9, which is to sit above this in their new X-series CPU stack.

This is actually where Intel have backed themselves into a corner by clocking the 7900X so impressively high. The 4.3GHz Turbo the chip happily runs at is way ahead of what they’re going to be able to do when Intel have to jam another two cores into the package, let alone the extra silicon needed to hit 14, 16, and 18 CPU cores.

More silicon in the same area means more heat and we know temps start to soar as higher frequencies are used. I can’t see the 12-core i9 7920X being able to hit 4.3GHz on an all-core Turbo out of the box, which will make the more expensive chip slower in a good few metrics. Intel have announced this 2.9GHz base clock for the 12-core chip, and I wouldn’t be surprised to see a Turbo of around 3.8GHz at most.

But, with all the competition noise around, it’s easy to forget that, only last year, a much slower, equivalent Intel CPU cost $1,700. That’s a massive change in pricing. If it wasn’t for the 16-core AMD processor retailing at the same price, it would’ve seemed like great value for the pro-sumer in desperate need of a lot of super-fast CPU cores. The fact Intel can ship this quicker chip at $700 less shows what a huge leap forward 2017 has been for processor silicon, but also how much Intel have been sandbagging over the last few generations.

I’m also a little nervous of the X-series platform as a whole. I’ve had some weird experiences during testing, there have been a lot of BIOS updates for the different X299 boards we’ve got in the office, and there have been a few instances of scary temperatures being reported in the power componentry of some boards.

The X299 release was a lot earlier than anyone anticipated, and I’m including the motherboard manufacturers in this, too. They will have been told they needed to shave a good couple of months off their X299 production times, and that will have meant rushing through production, and validation, in order to hit the new release schedule.

That will explain why there is such a shortage of boards around at the moment, even this long after the initial launch, and why early BIOSes would brick both CPU and motherboard in some instances.

So yeah, OMFG, that’s a mighty quick ten-core CPU for a lot less than it would’ve cost to get so many Intel cores last year. But you’d have to be an utter masochist to buy one.

Intel Core i9-7900X Review: Meet Skylake-X — Tom’s Hardware

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Early Verdict

Intel’s Skylake-X-based Core i9-7900X weighs in with 10 Hyper-Threaded cores and architectural enhancements that benefit many workstation-class workloads, such as rendering and content creation. But the processor struggles in some games compared to its predecessor, failing to match the Core i7-6950X in several titles.

  • Performance regresses in some games compared to prior generation

  • High price

  • Poor thermal performance

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Intel’s new Skylake-X processors span the Core i7 and i9 families, but all drop into the same LGA 2066 interface, enabled by the X299 chipset. They’re aimed specifically at high-end desktop users who need anywhere from four to 18 physical cores. Meanwhile, existing Skylake-S processors soldier on, popping into LGA 1151-equipped motherboards for mainstream desktops.

The company claims that several architectural enhancements to Skylake-X provide as much as 15% more performance than Broadwell-E in single-threaded workloads, while heavily-threaded tasks should be up to 10% faster.

  • AMD Ryzen 5 1600X (Silver AMD Ryzen 5) at Amazon for $160

Dominance in the high-end desktop segment began a decade ago for Intel. Since then, the CPU market has largely been a lopsided affair. Without much competition challenging its position, Intel never saw fit to cut prices or innovate aggressively. AMD’s return to the table with Ryzen changed that with more cores, SMT, and unlocked multipliers, all for less money.

Now Intel is looking to defend its flagship against the recently-announced AMD Threadripper CPU, sporting 16 cores, 32 threads, and 64 lanes of third-gen PCIe connectivity. Of course, the enhancements to Skylake-X aren’t any sort of knee-jerk reaction. These were in the works for years. Still, Intel moved on today’s announcement with unfamiliar speed (tripping on its laces in the process). It also adjusted pricing in a way we haven’t seen before. Enthusiasts, enjoy.


The 12+ core Skylake-X models are still on the distant horizon, and our Core i7-7440X was inexplicably delayed in shipping. That leaves us with the 10-core Core i9-7900X for today’s review. But first, let’s discuss the complete line-up of high-end options:

Kaby Lake-X

We aren’t accustomed to seeing current-gen architecture in the HEDT portfolio. Typically, the top models lag the mainstream chips by a generation or two. Dropping a pair of Kaby Lake-based chips into LGA 2066 changes this. Fortunately for fans of familiarity, everything else complementing the X299 platform controller hub is Skylake-based…though that could change soon. Earlier this year, Intel announced its ‘Data Center First’ strategy, which will see the newest processes coming to Xeon products before the desktop. Considering that the HEDT line-up consists of re-purposed data center dies, HEDT may become leading-edge.

In an unprecedented expansion, Intel grows its HEDT family from four models to nine, including those two Kaby Lake-X models. They’re a curious addition, supporting two DDR4 memory channels, whereas Skylake-X exposes four. That means you can only use half of your motherboard’s DIMM slots with a Kaby Lake-X CPU installed. Fewer PCIe lanes also result in restricted I/O options. Intel disables the on-die HD Graphics 630 engine, allowing the unused silicon to absorb heat and purportedly improve overclocking headroom. Aside from slightly higher base clock rates and a higher 112W TDP, the Core i5-7640X and i7-7740X are otherwise similar to their Skylake-S counterparts, right down to pricing.

In our opinion, matching «affordable» processors with expensive motherboards evokes images of the Core i3-7350K, which isn’t popular due to the same sort of imbalance. Intel tells us that motherboard manufacturers can build low-cost X299 platforms specifically for Kaby Lake-X, but we don’t see any of them scrambling to create such a niche product as of yet.

Core i5-7640X

Core i7-7740X

Core i7-7800X


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Intel supports DDR4-2666 on every Skylake-X CPU except Core i7-7800X, up from Broadwell-E’s official DDR4-2400 specification. It deliberately disables ECC in order to dissuade the Xeon crowd from adopting more enthusiast-oriented platforms.

Intel hasn’t released detailed specifications for the higher-end CPUs, but we expect it’ll expose similar memory specifications. We also expect frequencies to decline as core counts increase.

Active Cores 1 2 3 4 Cores 5-10
Intel Core i9-7900X (GHz) Turbo Boost 4.3 4.3 4.1 4.1 4.0

The Core i9-7900X features the same Turbo Boost 2.0 technology enabled on previous-generation processors, except that clock rates are notably higher this time around. Expect 4 GHz with 10 active cores. Intel also arms six of the Skylake-X models with Turbo Boost Max 3.0. The company improved this technology to target the two fastest cores running lightly threaded workloads. In Broadwell-E, Turbo Boost Max 3. 0 only accelerated a single core. Both favored cores max out at 4.5 GHz. Naturally, IPC throughput should be up quite a bit, addressing the big disadvantage Intel’s big HEDT chips sometimes suffered compared to its nimbler quad-core desktop SKUs. Currently, Turbo Boost Max 3.0 requires a driver on some motherboards. But Intel plans native Windows 10 support to eliminate this in the future.

We also get partial AVX-512 support, meaning the upcoming 18-core flagship should be the first desktop host processor enabling 1 TFLOPS+ of compute performance.

Skylake-X is notably different from Skylake-S in that its cache hierarchy is completely re-worked. Core i9-7900X sports more L2 and less L3, which should improve performance in most applications. A new 2D mesh architecture makes its debut as well. Like AMD’s Infinity Fabric, this architectural element isn’t a universal win, we’re finding (more on this shortly).

Whereas enthusiasts were dismayed to discover that the 10-core Core i7-6950X would sell for $1700+, they should be happy to learn of the 10-core Core i9-7900X’s $1000 price tag. Paying a cool grand is the only way to get 44 lanes of PCIe 3.0; stepping down to Core i7-7820X drops you to 28 lanes. As storage migrates to the PCIe bus, those extra lanes could come in useful for SSDs since multi-GPU configurations aren’t as popular these days. Intel does expose a new PCIe Virtual RAID on CPU (VROC) feature that allows you to coalesce up to 20 SSDs into a single bootable volume. Notably, you can assemble the RAID array on any available PCIe slot, whereas previous RSTe RAID implementations required a connection to the chipset. Sidestepping the chipset circumvents the bottleneck presented by DMI. This comes at a price, unfortunately. You’re forced to purchase an upgrade key that plugs into the motherboard to unlock VROC functionality. Server customers are familiar with this practice, but it’s not going to be popular among enthusiasts. We don’t even know what the key will cost yet.

Intel does reinstate DMI and PCIe bus overclocking, which should please power users. A new memory controller-PLL trim voltage setting is designed to increase ratio-based memory overclocking capabilities, while a new AVX-512 ratio offset joins the standard AVX offset to control thermals during taxing AVX-enabled workloads.

We encountered a few odd performance anomalies as we tested Core i9-7900X during the past week. This launch certainly feels rushed, and though motherboard firmware updates (from multiple vendors) addressed some of the oddities, others persist. It appears that Intel’s Skylake-X models will require a period of optimization, much like AMD’s Ryzen processors. Let’s take a look at the factors affecting Skylake-X’s performance.


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Intel Core i9-7900X Review « TOP NEW Review

When Intel’s Broadwell-E CPUs were released a year ago, they didn’t offer anything particularly new, aside from the 10-core Core i7-6950X, along with its ridiculously expensive price that broke the £1,500 barrier.

Charging that much money for a 10-core desktop CPU isn’t wise now though. This year, March saw the introduction of AMD’s Ryzen CPUs, which were not only just as quick clock-for-clock as their Intel counterparts in many tests, but also offered more cores for the same or less money. Now it’s Intel’s turn to hit back, with its brand-new Skylake-X range of chips, 10-core Core i9-7900X.

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There’s a more efficient 14nm manufacturing process in play

That 50 per cent drop in price could be due to several reasons. There’s competition from AMD, of course, with its new high-end desktop (HEDT) platform and Threadripper CPUs due to launch later this summer. However, there’s also a more efficient 14nm manufacturing process in play now, and the Core i9-7900X and Core i7-6950X are also quite different under the hood, much more so than the mainstream versions of Broadwell and Skylake.

There’s another reason, though, which is the fact that this 10-core CPU, unlike its predecessor, is a long way from being the flagship of Intel’s new HEDT platform. Intel has branched out above and below the usual three or four CPUs we normally see at the high end.

The real reason you’d splash out on Intel’s HEDT platform is clearly to get more cores, and maybe extra PCI-E lanes too – the latter are even more useful these days with PCI-E based storage being more popular.

For anyone who wants the full number of PCI-E lanes, which now sits at 44 – a rise of four over the X99 platform’s maximum – you now need to stump up a grand to buy the Core i9-7900X. Not even the 8-core Core i7-7820X has the full number of PCI-E lanes.

Clearly, then, Core i9 is the new naming scheme for CPUs with the maximum PCI-E lanes, but amazingly, the 7900X is the cheapest of the five CPUs in the range. Intel will also be releasing 12, 14, 16 and 18-core CPUs for the new X299 platform – the 12-core CPU will arrive in August and the rest in October, with the new flagship being the 36-thread Core i9-7980XE, with no UK pricing announced yet. The Core i9-7900X sports less L3 cache than the Core i7-6950X as well, but more L2 cache, which could make it more efficient in a range of tasks. Both CPUs have the same 140W TDP, but the new chip sports significantly higher clock speeds across the board. It has a 300MHz higher base frequency and all its cores can boost to a hefty 4GHz, which is 500MHz higher than the older CPU’s turbo frequency.

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There’s also a 500MHz advantage for the chip’s 2-core Turbo Boost Max Technology, meaning that two of this CPU’s cores can boost to 4.5GHz, compared to 4GHz for the Core i7-6950X.

Table of Contents

  • Performance
  • Conclusion
  • Verdict
  • Intel Core i9-7900X Review Benchmark


As you’d expect, there wasn’t much of a difference between the Core i7-6950X and new Core i9-7900X in our Gimp image editing test, which mainly relies on singlethreaded performance.

However, when all ten cores (and 20 threads with HyperThreading) kicked in, the Core i9-7900X produced some fantastic scores. It was more than 100,000 points faster than the Core i7-6950X in our heavily multi-threaded Handbrake video encoding benchmark, with the higher allcore turbo frequency clearing having a big impact, as well as the restructured cache.

The older CPU was a little faster in our multi-tasking benchmark, but that did little to dent the Core i9-7900X’s huge lead, with an overall system score of 230,352 compared to 205,205. Meanwhile, the 8-core Ryzen 7 1800X managed a respectable 174,195, which wasn’t far behind, despite costing half the price – a 10-core Ryzen CPU will likely be competitive here. In Ashes of the Singularity: Escalation, the older CPU had a lead, with a minimum frame rate of 45fps compared to 44fps, but in every other test, the Skylake-X CPU was utterly dominant. It was 12 per cent quicker in Terragen 4 and recorded a much higher score in Cinebench too.


Frequency 3.3GHz
Turbo frequency 4.5GHz
Core Skylake-X
Manufacturing process 14nm
Number of cores 10 x physical (20 threads)
Hyper-Threading Yes
Cache 13.75MB L3 cache, 10MB L2 cache
Memory controller Quadchannel DDR4, up to 2666MHz
Packaging Intel LGA2066
Thermal design power
(TDP) 140W
Features Turbo Boost Technology 2, Turbo Boost Technology 3, FMA3, F16C, SHA, BMI / BMI1 + BMI2, AVX-512, AVX2, AVX, AES, SSE4a, SSE4, SSSE3, SSE3, SSE2, SSE, MMX

When all ten cores kicked in, it produced some fantastic scores

We then wanted to see how far we could overclock this 10-core monster, and we managed to hit 4. 6GHz with a vcore of 1.24V, which is 200MHz higher than we managed with the Core i7-6950X, and with significantly less voltage too. However, the fact that Intel has used thermal paste and not solder between the CPU and heatspreader was very evident, as the new CPU got hotter much more quickly than the Broadwell-E CPU, even at lower voltages. Still, temperatures were easily tameable at 4.6GHz across all ten cores with an all-in-one liquid cooler, making for an awesomely powerful CPU.

This overclock saw the system score rise over 12 per cent to 258,546, which was over 5 percent faster than the overclocked Core i7-6950X. The Cinebench score rose by nearly 300 points too, giving it a near 200-point lead over the older CPU at 2,476 compared to 2,215.

However, Ashes of the Singularity remained stubbornly low – once you get to this level of CPU power, it looks like you won’t get any faster performance. Under heavy loads, the new CPU was a good deal more power-hungry, though, drawing 270W from the wall compared to 196W for the Core i7-6950X, although the two chips’ power consumption was similar once overclocked, despite the new CPU enjoying a 200MHz clock speed advantage.


There’s no doubt that, despite some toasty temperatures and a higher power draw, the Core i9-7900X is a much faster CPU than the Core i7-6950X in nearly every area – significantly so in some cases. The all-core boost to 4GHz at stock speed is massively powerful, although in value terms, AMD’s Ryzen chips offer superior bang per buck, costing half as much money for just a 2-core deficit. That said, thanks to the redesigned cache and higher frequencies, Intel’s Skylake-X architecture looks like it could be faster than Ryzen, aside from just core counts.

Still, the new CPU isn’t twice as fast as the Ryzen chip, despite costing twice as much money, and if AMD gets its pricing right, we can expect a tantalising battle at the high end between Threadripper and Core i9. Intel’s Skylake-X CPUs also appear to be able to get to higher overclocked frequencies than their predecessors, and a solid 4.6GHz frequency will mean you’re only a little behind what a Core i7-7700K would manage. In short, the Core i9-7900X is a monster CPU that’s overclockable, and the potential for a 4.6GHz 10-core CPU is likely to make any enthusiast drool.

That said, if you have the money, and you want as much multi-threaded CPU power as possible, we recommend holding out a few months to see what the other Core i9 CPUs can offer, as well as AMD’s Threadripper chips.



Ten cores at 4.6GHz is an amazing achievement, giving you the best of all CPU worlds, and for a much lower price than the Core i7-6950X.

Intel Core i9-7900X Review Benchmark

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Intel Core i9-7900X Review

Ten cores at 4.6GHz is an amazing achievement, giving you the best of all CPU worlds, and for a much lower price than the Core i7-6950X.

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Intel Core i9-7900X review: The fastest chip in the world, but too darn expensive

Tech —

When eight-core Ryzen costs £300, do any of these new Intel chips make sense?

Mark Walton


Mark Walton

Intel’s latest 10-core, high-end desktop (HEDT) chip—the Core i9-7900X—costs £900/$1000. That’s £500/$500 less than its predecessor, the i7-6950X. In previous years, such cost-cutting would have been regarded as generous. You might, at a stretch, even call it good value. But that was at a time when Intel’s monopoly on the CPU market was as its strongest, before a resurgent AMD lay waste to the idea that a chip with more than four cores be reserved for those with the fattest wallets.

The i9-7900X—which debuts the «i9» moniker alongside the new X299 platform, replacing X99—is the most powerful consumer desktop chip money can buy. In nearly every benchmark, it delivers the highest scores. In multitasking and heavily multithreaded applications like photo editors, video editors, and 3D computer graphics, it ably demonstrates the appeal of more cores. But as a product, a piece of aspirational tech to flaunt on Reddit, Intel’s HEDT chips are far less alluring.

It doesn’t help that X299 is a confusing mess of chips, PCIe lanes, and consumer-unfriendly feature lockouts that hint at a rushed launch in the wake of increased competition from AMD. Nor does it help that, like Intel’s mainstream Kaby Lake architecture before it, Skylake-X offers little in the way of raw instructions-per-clock (IPC) performance improvement over Broadwell-E.

AMD’s Ryzen is far from perfect. But when you can buy eight cores that serve even the heaviest of multitaskers and content creators for well under half the price of an Intel HEDT chip, i9 and X299 are a hard sell (except, perhaps, to fussy gamers that demand a no-compromises system).

The question is: Are you willing to pay a premium for the best performing silicon on the market? Or is Ryzen, gaming foibles and all, good enough?

When is HEDT not HEDT?

Intel’s strategy for X299 is what you might call «confused,» but what I’d more accurately call a clusterf**k. Where there were two tiers of HEDT chips in the past—»K» and «X» variants of a Core i7 based on the same architecture—there are now three tiers: i5, i7, and i9, all with same «X» designation. That means, for the first time in a long time, Intel’s enthusiast platform supports quad-core processors. The i5-7640X offers four cores at 4.0GHz, while the i7-7740X offers four cores at 4.3GHz with hyperthreading.


The idea, according to Intel, is to give customers without the means to buy more expensive 8-core or 10-core chips a more reasonable entry point into X299 with a clear upgrade path. Except, instead of offering the full features of the X299 chipset to i5X and i7X owners—thus somewhat justifying the price premium over the mainstream chips—Intel has simply transplanted its existing i5-7600K and i7-7700K Kaby Lake processors onto the new LGA 2066 socket.

Specs at a glance Intel Core i9-7980XE Intel Core i9-7960X Intel Core i9-7940X Intel Core i9-7920X Intel Core i9-7900X Intel Core i7-7820X Intel Core i7-7800X Intel Core i7-7740X Intel Core i5-7640X
Architecture Skylake-X Skylake-X Skylake-X Skylake-X Skylake-X Skylake-X Skylake-X Kaby Lake-X Kaby Lake-X
Cores/Threads 18/36 16/32 14/28 12/24 10/20 8/16 6/12 4/8 4/4
Base Clock TBC TBC TBC TBC 3.3GHz 3.6GHz 3.5GHz 4.3GHz 4.0GHz
Turbo Boost 2.0 TBC TBC TBC TBC 4.3GHz 4.3GHz 4.0GHz 4.5GHz 4.2GHz
Turbo Boost 3. 0 TBC TBC TBC TBC 4.5GHz 4.5GHz N/A N/A N/A
L3 Cache TBC TBC TBC TBC 13.75MB 11MB 8.25MB 8MB 6MB
PCIe Lanes TBC TBC TBC TBC 44 28 28 16 16
Memory Support TBC TBC TBC TBC Quad Channel DDR4-2666 Quad Channel DDR4-2666 Quad Channel DDR4-2666 Dual Channel DDR4-2666 Dual Channel DDR4-2666
TDP TBC TBC TBC TBC 140W 140W 140W 112W 112W
US Price $2000 $1700 $1400 $1200 $1000 $599 $389 $339 $242
UK Price ~£1800 ~£1600 ~£1300 ~£1100 £900 £550 £360 £315 £240

Neither chip supports quad-channel memory. Both come equipped with the same miserly 16 PCIe lanes, limiting compatibility with many features of X299 motherboards. A fancy board might feature three x16 PCIe slots, space for multiple M.2 SSDs, and a swathe of IO. But with a quad-core Kaby Lake-X chip installed, a lot of it won’t work. To add insult to injury, Intel has removed the integrated GPU present in the i5-7600K and i7-7700K and upped the TDP to 112W.

This should result in better overclocking—and there is some evidence of that in extreme cases—but it’s hard to see the value for consumers. In real-world use with practical cooling, Kaby Lake and Kaby Lake-X can be overclocked to similar speeds. The integrated GPU, while not particularly useful for high-end gaming, is great for video encoding and decoding using Intel’s Quick Sync technology. That’s not to mention that Z270 motherboards are much cheaper than their X299 counterparts.

Unfortunately, there are further complications up the product stack. The six-core i7-7800X and eight-core i7-7820X—which are based on Intel’s older Skylake architecture—both support quad-channel memory, but only come with 28 PCIe lanes. As a point of differentiation between chips, this is nothing new. But now, with the addition of 16-lane chips, it’s another point of confusion. The result of this shuffle is that X299 CPUs, at least at the lower end, are priced close to Ryzen 7 and Ryzen 5 (which feature a total of 24 PCIe lanes), albeit with fewer cores on offer.

It’s not until you move up to the £900 i9-7900X that you get the full complement of 44 PCIe lanes with which to exploit the X299 platform. X299’s predecessor, X99, was a forward-looking chipset, introducing features like DDR4 memory that would eventually trickle down to mainstream chips. X299 isn’t quite as compelling—there’s no one feature that can be lorded over Z270 users—but the number of PCIe lanes on the chipset has been bumped up from eight to 24, which are connected to the CPU via Intel’s proprietary DMI connection.


Enlarge / Intel is charging for certain VROC features.

Enlarge / This isn’t confusing at all /s.

Mark Walton

The result is that X299 motherboards are blessed with a wealth of IO that includes multiple SATA ports, M.2 slots, PCIe slots, USB 3.1 ports, multiple Gigabit Ethernet ports, and in some cases Thunderbolt 3. The difficulty is finding out which ports and slots are connected directly to the CPU and which are connected via the DMI, should you care about the small latency and performance hit from the latter (most motherboard makers provide a block diagram for such matters).

On that note, Intel has introduced a new feature that ensures M.2 storage is connected directly to the CPU. Dubbed Virtual Raid On CPU, or VROC for short, the feature allows you to link several M.2 NVMe SSDs in a virtual RAID via a PCIe add-in card, running them directly to the CPU for super-fast speeds. Unfortunately, there is one rather large caveat: only RAID 0 is supported by default. For any other type of RAID array, Intel requires the purchase of a small VROC dongle, which sits in its own slot on the motherboard.

This is common practice in the enterprise world, but unheard of in consumer platforms. Consumers have a reasonable right to expect all integrated hardware features to work without the need to buy a physical key to unlock them. Pricing is yet to be confirmed, although early reports put it at between £100-£200—a significant markup over already expensive X299 motherboards.

While the i9-7900X is the most powerful chip available at launch, Intel has four more chips coming with 12, 14, 16, and 18 cores. That these chips are currently little more than a product name and a price (the 18-core i9-7980XE will cost an astonishing $2000/~£1800) is a strong indication that Intel was taken aback by AMD’s Threadripper, a 16-core chip due for release this summer.

There’s no word on clocks speeds, TDP, memory support, or the number of PCIe lanes for any of the top-of-the-line chips. They won’t even launch until the latter half of the year.

Intel’s Core i9-7900X CPU reviewed, part one

Intel’s Core X CPUs are here, and we’re kicking off this new era with the highest-end chip in the lineup so far: the Core i9-7900X. As it traditionally does for its high-end desktop platform, the company is repurposing silicon from its upcoming Skylake Xeons to serve as Skylake-X chips. That means some unusually large changes are in store for us enthusiasts as Skylake makes its transition from mainstream desktops to the data center.

The Core X family of CPUs needs a new socket, LGA 2066, and a new platform, called X299. We’ve already covered the Core X lineup and the X299 platform, as well as the entry-level Kaby Lake-X CPUs for that platform, in a dedicated article. The short take is that X299 is an evolutionary step forward from the X99 platform. It keeps that platform’s quad-channel memory support (out of a total of six on at least some Skylake-X dies) and pairs it with a chipset powered by a lot of the same DNA present in the Z270 platform. If you need to brush up on Core X before reading on, feel free.

Now, back to Skylake-X. The fundamental pipeline of this chip isn’t much different from the various Skylake and Kaby Lake desktop parts that we’ve known and loved for almost two years now. We never did a deep dive into the Skylake architecture, but compared to Haswell and Broadwell, the basic Skylake integer pipeline is wider and can have more going on at once. To prevent this wider engine from burning power on execution of the wrong instructions, Skylake also features a better branch predictor than Haswell and Broadwell, according to Intel.

The basic Skylake core as seen in the Core i7-6700K and friends. Source: Intel

That’s a gross oversimplification, of course, but it’s generally how Intel has improved its chips over the past few years. Let’s have a look at the big differences between mainstream and server Skylake CPUs now.

AVX-512 unhinges its jaw

The first big change in Skylake-X is support for the AVX-512 instruction set. These new instructions add important new capabilities to Intel’s SIMD implementation, including scatter-gather support, dedicated state and mask registers, and much, much more. To support this generation of AVX, the chip’s vector data registers are now twice as wide, and there are twice as many of them. These wider registers are fed with more load and store bandwidth. Skylake-X can now handle two 64-byte loads and one 64-byte store per cycle, compared to a single 64B load and a single 32B store per cycle in mainstream Skylake.

On top of its wider and more numerous registers, the Skylake-X core also has a dedicated AVX-512 fused multiply-add unit (FMA) on top of the pair of 256-bit-wide AVX FMA units in Skylake-S. This unit can only handle AVX-512 FMAs, and it resides on port five of the Skylake-X unified scheduler. Since the pair of 256-bit FMAs can execute a single AVX-512 FMA in parallel alongside the dedicated AVX-512 FMA unit, throughput for that common instruction is effectively doubled in the best case compared to mainstream Skylake.

The AVX register structure in Skylake-X CPUs. Source: Intel

While those performance improvements may sound impressive, real-world performance of AVX-512 has caveats. Firing up those monster SIMD units requires large amounts of power (and therefore produces more heat), so Skylake-X CPUs might be forced to clock below Intel’s specified Turbo speeds (or not Turbo at all) when executing AVX-512 instructions. That clock-speed tradeoff might result in lower-than-expected performance from AVX-512 code, and Intel says developers will need to be able to amortize the expected performance gain of their AVX-512 applications over time versus the clock-speed drop their code might incur. Mixed workloads with a small proportion of AVX-512 instructions in the overall mix are apparently not an ideal case for speedups from that SIMD hardware, either.  

Model Base








Max 3.0












TDP Socket




i9-7980XE 18/36 LGA 2066 $1999
i9-7960X 16/32 $1699
i9-7940X 14/28 $1399
i9-7920X 12/24 $1199
i9-7900X 3. 3 4.3 4.5 10/20 13.75MB 44 Quad-channel


140W $999
i7-7820X 3.6 4.3 4.5 8/16 11MB 28 $599
i7-7800X 3.5 4.0 NA 6/12 8.25MB Quad-channel


i7-7740X 4.3 4.5 NA 4/8 8MB 16 Dual-channel


112W $339
i5-7640X 4.0 4.2 NA 4/4 6MB $242

What’s more, not every Core X chip in the lineup will enjoy the same boost in SIMD performance from AVX-512. Only the Core i9 series of CPUs will ship with the dedicated AVX-512 FMA. The Core i7-7800X and Core i7-7820X will still have the wider registers for AVX-512, but they’ll only execute instructions using the pair of 256-bit AVX units common to all Skylake chips. This exercise in segmentation might surprise people expecting a uniform performance increase from AVX-512 across all the CPUs that support it. (The Kaby Lake-X Core i5-7640X and Core i7-7740X won’t support AVX-512 at all.)

 Because of those caveats, we may be waiting a while for mainstream desktop applications that can really take advantage of all the extra parallelism on offer from these new instructions. Scientific-computing, deep-learning, and financial-services folks will probably be drooling for AVX-512, but regular Joes and Janes probably won’t see any major speedups until companies recompile their software (at the very least). That assumes AVX-512 is coming to mainstream Intel CPUs, as well.


Bigger L2 caches for better performance

Skylake-X also has a much different cache allocation per core compared to its mainstream counterparts. Instead of the relatively small 256kB L2 cache (or mid-level cache, in Intel parlance) in Skylake-S and Broadwell-E, each Skylake-X core enjoys a whopping 1MB of private L2. In support of AVX-512, the bandwidth between the L1 data cache and the L2 cache has been increased to 128 bytes per cycle. On top of that size increase, Intel quadrupled the associativity of the cache from four ways in  to 16 ways in Skylake-X. Intel says the move to a larger private cache lets programmers keep usefully large data structures close to the core, and the result is higher performance. Pretty cut and dry.

Intel says it undertook this change because it felt its older architectures placed too much emphasis on data sharing through the L3 caches. In turn, Skylake-X’s architects reduced the shared last-level cache allocation to as much as 1.375MB per core, compared to as much as 2.5MB per core for Broadwell-E chips. This last-level cache isn’t inclusive of the L2 caches, and it serves as a victim cache for the L2. The tradeoff for this rebalancing of cache allocations is a higher L3 cache access latency, according to Intel.

Getting meshy

Finally, Intel is abandoning the ring topology it’s used to connect CPU cores in its many-core CPUs for several generations. In place of its ring, the company is introducing a new (or at least new outside of the Knights Landing accelerator) mesh interconnect topolgy that promises several improvements. First off, Intel says its mesh interconnect delivers lower latency and higher bandwidth than the ring bus, all while operating at a lower frequency and voltage. Those last two characteristics are important, because they should result in less power consumption from the interconnect portion of the chip as it scales up.

Intel also says that the mesh design also allows it to include units like I/O, inter-socket interconnects, and memory controllers in a modular, scalable way as core counts increase. The company claims the distribution of these elements across the chip using the mesh minimizes undesirable “hot spots” of activity that might ultimately constrain cores’ access to those critical resources, limiting performance.

Mesh architecture conceptual representation. Red lines represent horizontal and vertical wires connecting CPU components; green squares represent switches at intersections. Source: Intel

The mesh design should also offer a boon for applications that need to do a lot of inter-core communication. The last-level cache in Skylake-X is distributed across each core, and thanks to the more uniform access characteristics of the mesh, Intel claims that application developers no longer have to worry about non-uniform latencies when accessing data in those caches. Cores should also enjoy more uniform access characteristics when accessing the die’s I/O and memory controller, as well.

Multiple ring buses, as seen in high-core-count Haswell Xeons.

Previously, the shared L3 caches on a chip might have resided on different rings, requiring cores to communicate across the buffered switches formerly used to join discrete rings on the die. These switches added latency on top of that incurred by traversing the ring bus in the first place—something that Intel gave customers the opportunity to avoid in past chips with a “cluster-on-die” mode that turned each ring into something resembling a NUMA domain of its own. The mesh topology in Skylake-X should make headaches from the non-uniform distribution and access latencies of resources among rings a thing of the past.

As for characteristics of the Skylake-X silicon itself, Intel honchos clammed up when we asked about die size and transistor count. The company believes that disclosing this information will lead to unfounded conclusions from its competitors about the quality of their chip designs and process technologies compared to Intel’s. Only the paranoid survive, we suppose.


The Core i9-7900X and LGA 2066 in the flesh
We’ve already touched on the Core X CPU family and the X299 platform in depth, but it’s good to get an up-close look at the Core i9-7900X and Asus Prime X299-Deluxe motherboard that Intel has provided us for testing.  

Clockwise from upper left: Core i7-5960X, Core i7-6950X, Core i9-7900X, Core i7-7700K, Ryzen 5 1700X

Outwardly, little has changed that would help us identify the Core i9-7900X at first glance. The eagle-eyed will note more rounded corners on the edges of the integrated heat spreader, but that’s about it.

From left to right: Core i7-5960X, Core i7-6950X, Core i9-7900X

Flipping these chips over reveals a dense forest of surface-mounted components, but it’s otherwise hard to notice the extra 55 lands on the Core i9-7900X. If you want to count, we’ll wait.

That outward similarity might lead one to believe that LGA 2011 and LGA 2066 chips are interchangeable among X99 and X299 motherboards, and the LGA 2066 socket doesn’t help. The dimensions of the socket are the same as those of LGA 2011, but chips for that socket absolutely will not work with LGA 2066. Don’t make an expensive mistake by eyeballing it. The only things that builders can carry over from LGA 2011 systems are their DDR4 kits and cooling hardware.

Intel sent us home with Asus’ ultra-ritzy Prime X299-Deluxe motherboard to host the Core i9-7900X. This board boasts everything one might want out of a high-end platform: four USB 3.1 Gen 2 ports, built-in 802.11ac and 802.11ad Wi-Fi, tasteful RGB LEDs, and a bevy of PCIe x16 slots. Asus also offers two M.2 slots, one of which allows gumstick SSDs to stand up vertically for better cooling. Even if both M.2 slots are occupied, the horizontal M.2 SSD can still enjoy plenty of heat-dissipation potential thanks to an integrated heatsink for the slot and chipset. This mobo even comes with a Thunderbolt 3 card and an add-on fan control board with several extra headers.

Our testing methods

As always, we did our best to collect clean test numbers. We ran each of our benchmarks at least three times, and we’ve reported the median result. Our test systems were configured like so:

Processor Ryzen 7 1800X
Motherboard Gigabyte Aorus AX370-Gaming 5
Chipset AMD X370
Memory size 16 GB (2 DIMMs)
Memory type G. Skill Trident Z DDR4 SDRAM
Memory speed 3866 MT/s (rated)

3200 MT/s (actual)

Memory timings 15-15-15-35 1T
System drive Intel 750 Series 400GB NVMe SSD


Processor Intel Core i7-5960X Intel Core i7-6950X Intel Core i9-7900X


Intel Core i9-7900X


Intel Core i7-7700K
Motherboard Gigabyte GA-X99-Designare EX Asus Prime X299-Deluxe Gigabyte Aorus GA-Z270X-Gaming 8
Chipset Intel X99 X299 Z270
Memory size 32GB 16GB
Memory type G. Skill Trident Z


G.Skill Trident Z


G.Crucial Ballistix Elite


G.Skill Trident Z


G.Skill Trident Z


Memory speed 3600 MT/s (rated)

2666 MT/s (actual)

3200 MT/s
2666 MT/s 3200 MT/s 3866 MT/s (rated)

3200 MT/s (actual)

Memory timings 15-15-15-35 2T
16-18-18-38 2T
16-17-17-37 2T 16-18-18-38 2T 15-15-15-35 2T
System drive Corsair Neutron XT 480GB SATA SSD Samsung 960 EVO 500GB NVMe SSD Samsung 850 Pro 512GB SATA SSD Samsung 960 EVO 500GB NVMe SSD

They all shared the same common elements:

Storage 2x Corsair Neutron XT 480GB SSD

1x Kingston HyperX 480GB SSD

Discrete graphics Nvidia GeForce GTX 1080 Ti Founders Edition
Graphics driver version GeForce 382. 33
OS Windows 10 Pro with Creators Update
Power supply Seasonic Prime Titanium 1000W

Thanks to Intel, Corsair, Kingston, Asus, Gigabyte, Cooler Master, G.Skill, and AMD for helping us to outfit our test rigs with some of the finest hardware available.

Some further notes on our testing methods:

  • The test systems’ Windows desktops were set at a resolution of 3840×2160 in 32-bit color. Vertical refresh sync (vsync) was disabled in the graphics driver control panel.
  • For our Ryzen systems, we used the AMD Ryzen Balanced power plan included with the company’s most recent chipset drivers. We left our Intel systems on Windows’ default Balanced power plan.

The tests and methods we employ are usually publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.


Memory subsystem performance

Since Skylake-X has such a drastically different cache allocation versus its predecessors, we simply had to run it through SiSoft’s bandwidth and latency tests. We’ll start with the Sandra utility’s cache and memory bandwidth test.

To examine the effect of the increased L2 cache size in an intuitive way, we started with the single-threaded test. To interpret these results, remember that the block size identifies which level of cache the test is exercising. From 2KB to 32KB on all of these CPUs, we’re in the L1 cache. Past that point, we’re generally in L2 for most of these CPUs out to 256KB for Haswell, Broadwell, and Kaby Lake, 512KB for Zen, and 1MB for Skylake-X. Finally, we spill over into L3. 

The most interesting result in the chart above unsurprisingly ocurs between the 512KB mark and 1MB, where we’re testing most of these chips’ L2 caches. Thanks to their 1MB L2s, each Skylake-X core can sustain much higher bandwidths at the 1MB block size than the competition. Save for the Zen core, which is still in its L2 at 512KB, all of the older Intel chips are already into their L3 caches.

Sandra’s multithreaded cache and memory bandwidth test shows the combined bandwidth from every core on each chip. In turn, we have to account for the combined size of each cache level on each chip when mapping block sizes to the cache that we’re in at a given size. That’s because the same source block is being split among multiple cores. If that sounds complicated, it is, and there are a lot of moving parts to account for here between core counts and clock speeds. Still, this measurement is a good way of showing just how much data these chips can move around in total.

Because Sandra supports AVX-512 instructions, and because Skylake-X doubles the L1 cache load bandwidth available per core, we get much more throughput compared to older Intel CPUs at most block sizes. Since the test is still hitting the i9-7900X’s L1 cache from 64KB out to 256KB, for example, the increased load bandwidth for that cache lets the 7900X turn in incredible throughput increases across the chip. That trend continues as the test moves into the 7900X’s L2 cache, where it can move roughly 50% more data compared to the Core i7-6950X, itself no slouch. All told, the i9-7900X sets a high new bar for cache throughput—not an easy task in this company.

Next, let’s look at some tests of main memory bandwidth from the popular AIDA64 utility.

Interesting. Though the i9-7900X takes a commanding lead over the i7-6950X in AIDA64’s read tests with both DDR4-2666 and DDR4-3200 RAM, the Skylake-X chip falls slightly behind Broadwell-E in write bandwidth, and it needs DDR4-3200 to match the i7-6950X in the copy test. None of these chips are slouches, to be sure, but the results for the i9-7900X aren’t quite as eye-popping as they were in Sandra’s cache tests. Time to talk latency.

Sandra also offers a detailed benchmark for cache and memory latencies. To reduce the effect of prefetching on this result, we use the “in-page random” access pattern. Like the single-threaded cache bandwidth test above, this test isn’t multithreaded, so it’s easy to keep track of what cache is being measured at each block size. 

As Intel suggested it would, the L2-L3 rebalancing on Skylake-X offers more bandwidth from its L2 caches at the same latency as before, at the cost of slightly higher latencies in the L3. Seems like a fine tradeoff to us, given the apparent benefits of the larger L2.

Compared to past Intel architectures, Skylake-X lags in main-memory access latencies. That increase may be offset somewhat by the potentially much higher hit rate in the L2 cache, though.

Some quick synthetic math tests

AIDA64 offers a useful set of built-in directed benchmarks for assessing the performance of the various subsystems of a CPU. The PhotoWorxx benchmark uses AVX2 on compatible CPUs, while the FPU Julia and Mandel tests use AVX2 with FMA.


PhotoWorxx doesn’t seem to benefit from the improvements in the Core i9-7900X, but the Skylake-X CPU enjoys a commanding lead in our tests of floating-point prowess. At least in these synthetics, the i9-7900X seems to justify its more-than-twice-the-price tag of the Ryzen 1800X. Let’s see if this strong opening translates into real-world performance now.


Javascript performance

The usefulness of Javascript benchmarks for comparing browser performance may be on the wane, but these collections of tests are still a fine way of demonstrating the real-world single-threaded performance differences among CPUs. These tests may be an ideal stage for Skylake-X’s improved Turbo Boost Max 3.0 implementation.

Turbo Boost Max 3.0 doesn’t go all the way toward eliminating the single-threaded performance gap we tend to see between mainstream and high-end Intel chips using the same architecture, but the feature does let the i9-7900X get most of the way there—and in Kraken, the Skylake-X chip does catch the i7-7700K. That’s good news for folks who like a responsive machine in both lightly-threaded and all-out workloads.

Compiling code in GCC

Our resident code monkey, Bruno Ferreira, helped us put together this code-compiling test. Qtbench records the time needed to compile the Qt SDK using the GCC compilers. The number of jobs dispatched by the Qtbench script is configurable, and we set the number of threads to match the hardware thread count for each CPU.

Bang. The i9-7900X neatly shaves 20% off the compile time of our previous champion, the Core i7-6950X, and it does it for hundreds of dollars less.

7-Zip file compression

Put the i9-7900X to work zipping and unzipping archives, and it delivers a small-to-moderate boost over its Broadwell predecessor. Memory speeds don’t seem to make the least bit of difference to the 7900X’s performance, though.

VeraCrypt disk encryption

VeraCrypt is a continuation of the handy TrueCrypt project. This disk-encryption utility lets us test throughput for both the hardware-accelerated AES algorithm and the implemented-in-software Twofish cipher.

The AES half of our VeraCrypt testing does appear to be memory-bound for once, so DDR4-3200 allows for a whopping 2.4 GB/s higher throughput. Twofish doesn’t enjoy any such speedup from faster memory, although the i9-7900X still handily pulls away from the i7-6950X.



The Cinebench benchmark is powered by Maxon’s Cinema 4D rendering engine. It’s multithreaded and comes with a 64-bit executable. The test runs with a single thread and then with as many threads as possible.

In Cinebench’s single-threaded test, the i9-7900X once again proves its Turbo Boost mettle against the Core i7-7700K. Core for core, the Skylake-X chip also hands in a roughly 16% improvement over the Core i7-6950X. Pretty darn good considering the low-single-digit performance improvements we’ve come to expect from Intel’s generation-to-generation advances.


Blender is a widely-used open-source 3D modeling and rendering application. The app can take advantage of AVX2 instructions on compatible CPUs. We chose the “bmw27” test file from Blender’s selection of benchmark scenes to put our CPUs through their paces.

The i9-7900X carves up our test file in fine form with a 12.5% decrease in render time over its predecessor. The i7-6950X is probably looking at its original suggested price tag and sweating a bit by now. Once again, faster memory makes no difference in performance for the i9-7900X.

Handbrake video transcoding

Handbrake is a popular video-transcoding app that recently hit version 1.0. To see how it performs on these chips, we’re switching things up from past reviews. Here, we converted a roughly two-minute 4K source file from an iPhone 6S into a 1920×1080, 30 FPS MKV using the HEVC algorithm implemented in the x265 open-source encoder. We otherwise left the preset at its default settings.

Noticing a pattern yet? The i9-7900X completes this job in 14% less time than the i7-6950X needs, and its performance doesn’t vary with memory speed.



It’s been a while since we tested CPUs with picCOLOR, but we now have the latest version of this image-analysis tool in our hands courtesy of Dr. Reinert H.G. Mueller of the FIBUS research institute. This isn’t Photoshop; picCOLOR’s image analysis capabilities can be used for scientific applications like particle flow analysis. In its current form, picCOLOR supports AVX2 instructions, multi-core CPUs, and simultaneous multithreading, so it’s an ideal match for the CPUs on our bench. Check out FIBUS’ page for more information about the institute’s work and picCOLOR.

picCOLOR offers an interesting shake-up in our results for once. Although the i9-7900X still totally outruns every other chip in our stable, this time it’s trailed by the Ryzen 7 1800X instead of the Core i7-6950X. Faster memory still doesn’t do squat for the 7900X, though.


Euler3D tackles the difficult problem of simulating fluid dynamics. It tends to be very memory-bandwidth intensive. You can read more about it right here. We configured Euler3D to use every thread available from each of our CPUs.

Interesting. Euler3D seems to lean on the memory subsystem in ways that are particularly amenable to high performance with the i7-6950X and not so much so for the i9-7900X. Not every workload benefits from Intel’s rebalanced cache hierarchy with Skylake-X, it seems.

Digital audio workstation performance

DAWBench is a popular addition to our CPU test suite, and we’re now working directly with the creator of DAWBench, Vin Curigliano, to refine our testing methods. As part of that collaborative effort, Vin provided us with a beta version of the DAWBench DSP 2017 benchmark. We’re leaving DAWBench’s virtual instrument test on the bench this time around, however, since these high-powered Intel CPUs tend to max out the benchmark and an updated version of the test isn’t quite ready yet.

DAWBench DSP 2017 relies on the freely-available Shattered Glass Audio SGA1566 VST plugin. We used the 64-bit version of this VST in our testing. DAWBench DSP lets us enable instances of this plugin until the session becomes unresponsive. We used Reaper as our host DAW for the test, and we monitored the project using a Focusrite Scarlett 2i2 interface with the company’s latest USB ASIO drivers. We set a 96 KHz sampling rate and used two ASIO buffer depths: a punishing 64 and a slightly-less-punishing 128.

As we’ve come to expect, the i9-7900X delivers a modest performance improvement in this test versus the Core i7-6950X. Strangely, the 7900X-and-DDR4-3200 pairing actually performs worse than its DDR4-2666-equipped configuration, though. We’ll have to monitor this test and see whether it’s a behavior that changes as the X299 platform matures.


A quick look at power consumption and energy efficiency

Skylake-X’s performance improvements wouldn’t be worth much if they came with a corresponding decrease in energy efficiency. We can get a rough idea of whether the Core i9-7900X is as efficient as it is fast by monitoring our test system’s power consumption at the wall with our trusty Watts Up power meter and estimating the total amount of energy it needs to complete a task. Our observations have shown us that Blender consumes about the same amount of power at every stage of the bmw27 benchmark we test with, so it’s an ideal guinea pig for this kind of calculation. First, though, let’s check idle and peak load power consumption numbers.

At idle, the X299 platform paired with the Core i9-7900X sips only a bit more power than the Core i7-7700K. Under load, however, the 7900X system consumes the most power at peak load by a wide margin. Of course, peak power draw only tells part of the efficiency story.

To really get a sense of how efficient the Core i9-7900X is, we need to take the task energy consumed over the course of our Blender benchmark into account. Not only does the Core i9-7900X cut 94 seconds off the Ryzen 7 1800X’s bmw27 render time, it does it while expending only just a bit more power to do so. That’s impressive performance per watt.



It’s time once more to sum up our results using our famous scatter plots. To spit out this final index, we take the geometric mean of each chip’s results in our real-world productivity tests, then plot that number against retail pricing gleaned from Newegg. Where Newegg prices aren’t available, we use a chip’s original suggested price.

Our value scatter tells the entire story of the Core i9-7900X: if your workload scales to many threads, this chip is generally the one to run it on. The server version of Skylake delivers an unusually large performance boost for a modern Intel CPU revision in many tasks. Core for core and thread for thread, the already-beastly Core i7-6950X can sometimes lag the 7900X in the range of 10% to 20%. All that oomph comes for a jaw-dropping $724 less than the 6950X’s initial suggested price, too. Competition is a wonderful thing.

In a milestone for Intel’s high-end desktop platform, the Core i9-7900X mostly ends the tradeoff between single-threaded swiftness and multi-threaded grunt typical of some older Intel high-end desktop chips. For lightly-threaded workloads, the i9-7900X’s improved Turbo Boost Max 3.0 behavior lets it trail our single-thread-favorite Core i7-7700K by only a few percentage points at most. In typical desktop use, then, the i9-7900X and its TBM 3.0-enabled brethren should feel about as snappy as their mainstream desktop cousins. I need to get the i9-7900X paired up with a GeForce GTX 1080 Ti soon to see whether that single-threaded performance translates to similar gameplay smoothness.

I’ll also need to explore Skylake-X overclocking in depth soon. Thanks to immature firmware and monitoring utilities, I didn’t feel comfortable pushing my 7900X too hard at this point. That said, I see a lot of promise for overclocking this chip. My test system made it to the Windows desktop without a hiccup at an astounding 4. 7 GHz on all cores, and thermal limits seem as though they’ll be the primary obstacle to fully exploiting that speed. I’ll explore Skylake-X’s overclocking potential more once the X299 platform has had a bit more time in the oven (and once I’ve picked up some seriously beefy cooling hardware in the meantime).

We’ve always been loath to recommend the top-end CPU in Intel’s high-end desktop family (and yes, that is this chip for the moment). Despite the Ryzen-inspired price reshuffling that’s coming with Core X, the i9-7900X still isn’t a great value. The star of the Core X lineup may actually be the Core i7-7820X, whose eight cores and 16 threads have clocks similar to those of the i9-7900X. You may lose a couple of cores in the bargain, but even so, the i7-7820X should perform better than a Ryzen 7 1800X for not that much more money. We hope to play with one of these more attainable Skylake-X CPUs soon.

Of course, the performance of the Core i9-7900X is beyond question: it’s the fastest single-socket CPU we’ve ever tested. The X299 platform may need a little polish yet to let Core X chips really shine, but the performance bar the i9-7900X is already setting promises an exciting standoff this summer as AMD prepares its Ryzen Threadripper CPUs for launch. If you need as many cores and threads as possible from your desktop, times have never been more exciting. Stay tuned as we see whether the i9-7900X has got game.


Article Rating

Intel Core i9-7900X (Skylake-X) Review


Not much has changed in overclocking terms compared to Broadwell-E. For a quick boost, you can simply increase the multiplier, set a vcore, and away you go. However, there are also the usual PEG/DMI ratios if you’ll be fiddling with the baseclock, from which the PEG/DMI clock are derived and which can affect stability. However, with the Kaby Lake-X CPUs, the PCI-E clock is fixed at 100MHz no matter what you do with the baseclock.

There seems to be much more headroom with Skylake-X than its predecessor, and the main limiting factor is temperature if our CPU is anything to go by. We plumbed in 1.3V as a starting point and crept up from 4GHz all the way to an astounding 4.7GHz, which is 300MHz higher than we managed with the Core i7-6950X. Even more impressive was the fact that it was still completely stable with just 1.28V — far lower than the 1.44V we needed with the older CPU.

However, temperatures were definitely a concern with Cinebench and Terragen pushing 100°C with our 240mm AIO liquid cooler. As a result, while stable and potentially tameable under custom water-cooling, we decided to go for 4.6GHz for benchmarking, which required a super-low 1.22V. Interestingly our Core i7-6950X ran much cooler despite using a significantly higher voltage, albeit at 4.4GHz. This could well be due to thermal paste having been used between the heatspreader and CPU core with the new Skylake-X CPUs, in which case delidding could potentially yield significant benefits given the high heat density.

Indeed, as we were writing this, overclocker der8auer released a video on YouTube of him successfully delidding a Core i9-7900X and achieving a 5GHz overclock using an off-the-shelf AIO liquid cooler. If you’re prepared to risk it with your £1,000 / $1,000 CPU, then there are likely serious gains to be had.

Performance Analysis

Edit: We discovered that despite both our X99 and X299 test systems being set to the default Windows 10 balanced profile, the X299 system seemed to suffer in some tests compared to using the high performance profile. As such, we’ve re-run all the tests and updated scores for CPU-Z, Fallout 4, 3DMark Time Spy and PCMark 10 photo editing, all of which improved on the X299 system

We’re in the process of transitioning to some new benchmarks and have also added an Nvidia GTX 1080 into the mix since our recent Ryzen testing, so some of our graphs currently have fewer results in than others. However, in all our tests we have the three main fight-hungry CPUs — the two Intel 10-cores, the Core i7-6950X and Core i9-7900X, and, as AMD’s Threadripper is still absent, we’ve decided to include the eight-core Ryzen 7 1800X.

Starting with our content creation tests, the fact that the Intel Core i9-7900X can run all cores at an impressive 4GHz at stock speed means that it’s pretty potent out of the box. It was much faster than the Core i7-6950X in the HandBrake 4K video transcoding test, shaving 11 seconds off the latter’s 71-second completion time. It was also quicker in the PCMark 10 photo editing test.

The Skylake-X domination continued, though, with some awesome times in Terragen 4 — out of the box, the Core i9 was faster than an overclocked Core i7-6900K, and again it was significantly quicker than the Core i7-6950X thanks to that massive advantage in all-core boost. It was a similar story in Cinebench — only the overclocked Core i7-6950X was faster.


If Skylake-X appeared in a year’s time as a blatant reaction to AMD’s shenanigans, one would rightly suggest that what we’ve seen today is an indicator of Intel ramping things up to prevent AMD eating into its market share. However, Skylake-X has landed barely a couple of months after Ryzen — it’s not been created in 12 weeks but has been on the cards for a long time, certainly way before the Ryzen hype train arrived in 2016 leading up to the March launch this year.

As a result, this beastly CPU can be considered a real, genuine challenge for AMD and for several reasons. Firstly, it costs 50 percent less than its predecessor, so complaints about Intel’s CPUs being pricey are clearly being addressed somewhat, especially as the restructured cache and higher clock speeds offer much better performance in many tests, and it’s also a better overclocker if our sample is anything to go by. It’s likely going to be more expensive than the equivalent AMD Threadripper in terms of cores and threads, but Intel has the advantage in core speed both at stock speed and almost certainly when overclocked too, unless Threadripper can summon 4.5GHz all-core overclocks from somewhere.

The fact that you can get a 10-core CPU to 4. 6GHz with relative ease at less than 1.25V with a decent cooler is remarkable, and we have no doubt that it’s the lack of solder between the heatspreader and core that’s holding things back. Thankfully, the Core i9-7900X still represents a big leap in performance in many real-world tests, especially video transcoding and rendering both at stock speed and when overclocked despite thermals limiting overclocking.

So, we’ve established that the Core i9-7900X is potentially a great overclocker and has superb performance at stock speed too, but what about Intel versus AMD? Well, in games such as Fallout 4, there’s still very little difference. The Ryzen 7 1800X was a little slower in Ashes of the Singularity and Deus Ex, even when overclocked. However, the real question is value. The Core i9-7900X is more than twice the price of the Ryzen 7 1800X, yet in Terragen 4, Cinebench, and HandBrake and in games, it’s far from being twice as fast. In fact, the deficits are almost exactly what we’d expect from a two-core/four-thread deficit.

We can’t really speculate on Threadripper, of course, but with rumours pointing to an August launch, if you’re in the market for a high-end system, it could well be worth waiting. In the meantime, though, Intel has shown its hand, and it’s a very good one indeed.

1 — Intel Core i9-7900X Review2 — Intel Core i9-7900X Review — Cache Restructuring and Improved Turbo Max Boost 3.03 — Intel Core i9-7900X Review — Test Setup4 — Intel Core i9-7900X Review — Media Creation and Synthetic Tests5 — Intel Core i9-7900X Review — Rendering Performance6 — Intel Core i9-7900X Review — 3D Performance7 — Intel Core i9-7900X Review — Power Consumption8 — Intel Core i9-7900X Review — Overclocking, Performance Analysis, and Conclusion

Intel Core i9-7900X vs. Core i7-7740X

Ten cores versus four

Earlier we wrote that at Computex 2017, Intel unveiled information about a new platform code-named Basin Falls, which includes the Intel X299 chipset and the new Intel Core-X processor family (Skylake-X and Kaby Lake-X) with Moreover, we even tested the quad-core Intel Core i7-7740X (Kaby Lake-X) processor and compared its performance with Kaby Lake processors with LGA 1151 socket.

Recall that based on the test results, we made a simple conclusion: the Intel Core i7-7740X processor is an analogue of the Intel Core i7-7700K processor, but with a different socket and without a graphics core (or with a blocked graphics core). The Intel Core i7-7740X and Intel Core i7-7700K processors provide nearly identical performance across all applications. Moreover, it turned out that the overclocking potential of the Intel Core i7-7740X and Intel Core i7-7700K models is also the same, and they are practically the same in terms of power consumption (despite the slightly different declared TDP value).

In this article, we will review the results of testing the 10-core Intel Core i9-7900X (Skylake-X) processor and compare its performance with the Intel Core i7-7740X (Kaby Lake-X). In addition, such an important aspect as power consumption and overclocking potential of these processors will be considered.

Brief specifications of the compared processor models are shown below.

Processor Core i7-7740X Core i9-7900X
Process technology, nm 14 14
Connector LGA 2066 LGA 2066
Number of cores 4 10
Number of threads 8 20
L3 cache, MB 8 13.75
Rated frequency, GHz 4.3 3.3
Maximum frequency in Turbo Boost mode, GHz 4.5 4.3
Turbo Boost Max 3.0 GHz 4.5
TDP, W 112 140
DDR4 memory frequency, MHz 2666 2666
Number of memory channels 2 4
Maximum memory, GB 64 128
Number of PCIe 3.0 lanes 16 44
Command set extensions SSE4. 1/4.2, AVX 2.0 SSE4.1/4.2, AVX 2.0, AVX-512
Graphics core
Estimated cost $339 $999
Average price

ask price

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Performance and power study

To test the Intel Core i7-7740X and Intel Core i9-7900X processors, we used the following configuration:

Motherboard Asus Prime X299-Deluxe
Chipset Intel X299
Memory 16 GB DDR4-2400
Graphics subsystem MSI GeForce GTX 1070 Gaming X 8G
Accumulator SSD Seagate ST480FN0021 (480 GB)
Operating system Windows 10 Pro (64-bit)

Of the two boards we have in stock based on the Intel X29 chipset9 (Asus Prime X299-Deluxe and X299 Aorus Gaming 9), we chose the Asus board because it turned out that the Intel Core i7-7740X processor could run stably at 5 GHz on it, while on the X299 Aorus Gaming 9 it was stable this processor was only achieved at a frequency of 4. 9 GHz.

Since the Intel Core i7-7740X and Core i9-7900X processors are overclockable, they were tested in both default and overclocked modes. Moreover, the Core i9-79 processor00X has a 4-channel memory controller, while the Core i7-7740X processor is only dual-channel, so the Core i9-7900X processor was tested once in quad-channel memory mode and the second time in dual-channel mode.

Processors were overclocked by changing the multiplier for all cores simultaneously. For the Intel Core i7-7740X processor in the overclocked state, the frequency was 5 GHz, and for the Core i9-7900X processor, stable operation in the overclocked state was achieved at 4.6 GHz. Let’s clarify that Core i9The -7900X also ran at 5GHz, but it only passed all tests at 4.6GHz.

In addition to testing processors for performance, we also measured their power consumption, for which we used a specialized hardware and software measuring unit, which was connected to the break in the power circuits between the computer power supply and the motherboard. That is, the measuring unit was connected to the 24-pin (ATX) and 8-pin (EPS12V) connectors of the power supply, and the motherboard was already connected to the measuring unit using similar connectors. The measuring unit is able to measure the voltage and current on the 12 V, 5 V and 3.3 V buses of the ATX connector, as well as the supply voltage and current on the 12 V bus of the ATX12V/EPS12V connector used to power the processor. Communication of the measuring unit with the computer is carried out via the USB bus. This allows you to control the operation of the block and save the measured values ​​in a file. The operation of the measuring unit is controlled from the command line.

In each test using the software and hardware unit, the total power consumption and the power consumed by the processor were determined. The total power consumption during the test is the power consumed on the 12V, 5V and 3.3V buses of the ATX connector and the 12V bus of the EPS12V connector. The power consumed by the processor alone during the test is the power consumed by the 12 V rail of the EPS12V connector (this connector is used to power the processor). However, it should be borne in mind that in this case we are talking about the power consumption of the processor together with its voltage regulator. Naturally, the voltage regulator has a certain efficiency, and part of the electrical energy is consumed by the regulator itself (released as heat on MOSFETs and other elements). Thus, the real power consumed by the processor itself will be slightly lower than the values ​​measured by us, however, it is not possible to measure this real value using an external measuring unit.

CPU testing was done using our iXBT Application Benchmark 2017 real-life benchmark and iXBT Game Benchmark 2017 game suite. Recall that the error of the result is calculated with a confidence level of 95%.

Logic test group Core i9-7900X (2-channel memory mode) Core i9-7900X (4-channel memory mode) Core i9-7900X
Core i7-7740X Core i7-7740X
@5 GHz
Video conversion, points 218±4 219. 2±1.4 248.7±2.4 110.5±0.4 121.6±0.4
MediaCoder x64, since 47.3±1.5 47.0±1.4 42.0±0.8 96.0±0.5 87.0±0.5
HandBrake 0.10.5, from 48.5±0.2 48.2±0.3 41.9±0.2 92.9±0.4 84.6±0.4
Rendering points 221.0±1.0 220.7±1.5 240.4±0.9 111.2±0.2 122.8±0.3
POV-Ray 3.7, from 57.5±0.3 57.6±0.5 55.5±0.1 124.4±0.3 112.0±0.3
LuxRender 1.6 x64 OpenCL, since 102.0±0.5 102.0±0.5 97.0±0.7 228±0.5 206.3±1. 4
Blender 2.77a, from 121.7±1.6 121.9±2.3 102.9±0.9 197.5±0.5 179.8±0.6
Video editing and video content creation, points 160.5±0.9 162.1±0.8 177.7±1.5 114.5±0.4 126.6±0.5
Adobe Premiere Pro CC 2015.4, since 54.6±0.2 54.1±0.3 49.1±0.1 97.0±0.9 88.0±0.1
Magix Vegas Pro 13, with 179.3±1.4 173±4 175.0±1.1 318.0±0.8 290±5
Magix Movie Edit Pro 2016 Premium v., from 138±4 138.0±0.3 119±5 169.4±1.6 150.4±1.0
Adobe After Effects CC 2015.3, from 302.3±0. 5 301.0±1.7 262.0±1.5 506±47 457.0±2.5
Photodex ProShow Producer 8.0.3648, since 272.0±2.5 271.7±1.4 249.0±0.7 227.0±2.3 207.7±1.4
Digital photo processing, points 105.4±0.8 109.3±1.0 117.2±0.5 104.0±0.4 111.7±0.4
Adobe Photoshop CC 2015.5, from 515±7 510±3 404.3±1.3 413.4±1.8 378.2±2.4
Adobe Photoshop Lightroom CC 2015.6.1, since 211±3 202±4 194.2±1.7 233.5±1.7 222.0±0.9
PhaseOne Capture One Pro, with 237.8±2.3 224.9±2.9 238.7±1.9 277.8±2.5 257. 9±1.6
Text recognition, points 253.4±0.4 253.6±0.2 272.8±1.9 111.6±0.2 122.9±0.2
Abbyy FineReader 12 Professional, with 174.6±0.3 174.5±0.1 162.1±1.1 396.2±0.7 359.9±0.4
Archiving, points 110.6±0.4 112.4±1.0 154.7±0.3 103.2±0.7 106.4±1.1
WinRAR 5.40 CPU, since 82.9±0.3 81.6±0.8 59.2±0.1 88.8±0.6 86.2±0.9
Scientific calculations, points 160.3±1.9 177. 8±1.3 169.1±1.4 104.4±2.2 115.6±1.6
LAMMPS 64-bit 20160516, from 205.0±2.8 184.4±2.9 205±4 369±3 337.8±4.1
NAMD 2.11, from 101.5±0.9 100.2±0.8 98.7±2.0 212±4 191.9±3.0
FFTW 3.3.5, ms 25.7±1.4 17.2±0.5 25.9±0.4 38±4 32.4±2.1
Mathworks Matlab 2016a, since 70.2±0.2 70.2±0.8 59.8±1.0 106±3 96.6±0.5
Dassault SolidWorks 2016 SP0 Flow Simulation, with 228.6±2.5 229.3±1.3 210±4 233±2.9 217±4
File operations speed, points 90.8±2.1 89. 9±1.6 98.7±0.9 101.8±2.1 99.4±2.4
WinRAR 5.40 Storage, since 89.7±2.0 89.9±1.9 89.2±1.2 85.3±1.3 91.9±2.0
UltraISO Premium Edition, from 60.1±1.4 61.5±2.7 51.3±0.9 50.2±2.8 49.6±1.3
Data copy speed, s 45.6±2.8 45.9±0.8 41.9±0.6 40.8±1.0 41.2±2.6
Integral result of CPU, points 167.3±0.5 171.4±0.4 189.9±0.5 108.4±0.4 118.0±0.3
Storage integral result, points 90.8±2.1 89.9±1.6 98.7±0.9 101. 8±2.1 99.4±2.4
Integral performance result, points 139.2±1.0 141.2±0.8 156.0±0.5 106.4±0.7 112.1±0.8

Analysis of the results according to the above table is difficult, so we will also present the integral test results on the diagrams for each logical group of tests.

As can be seen from the comparison of the results of testing the Core i9-7900X processor in dual-channel and quad-channel memory modes, doubling the memory bandwidth does almost nothing. That is, four memory channels is, of course, very cool, but it would be nice to find applications that need it. The only tests in which increasing memory bandwidth leads to an increase in the result are LAMMPS (reduction of test execution time by 10%) and FFTW (reduction of test execution time by 33%). But these are very specific applications. In all «household» tests, the four-channel operation mode does not provide acceleration relative to the two-channel one. Actually, the result is quite predictable: there are not many applications for which even the transition from single-channel DDR4 memory to dual-channel can significantly affect the performance. That is, the bandwidth of DDR4 memory in dual-channel mode in many cases is more than enough. The analogy here is this: if there is only one lane on the road, but there are few cars, then adding a few more lanes will not lead to an increase in the speed of cars. Considering that the four-channel mode provides almost the same results as the two-channel mode (the difference in the integral result is only 2.5% in favor of the four-channel mode), testing the Core i9 processor-7900X was only overclocked with dual-channel DDR4-2400 memory.

Overclocking the Core i9-7900X to 4.6 GHz results in a 13.5% increase in performance — in the overclocked state, this processor scores 189. 9 points of the integrated CPU performance result. To date, this is a kind of record. As a reminder, our iXBT Application Benchmark 2017 test suite uses a Core i7-6700K-based computer with 16 GB of DDR4-2133 memory and no discrete graphics as a reference system. That is, a computer based on a 10-core Core i9 processorThe -7900X is about 90% faster than our reference system.

Now let’s look at the test results of the 4-core processor Core i7-7740X. First of all, overclocking it to 5 GHz leads to a performance increase of almost 9%, which is not bad. But more interesting is the performance comparison between Core i7-7740X and Core i9-7900X. In the absence of overclocking, the Core i9-7900X processor outperforms the Core i7-7740X processor by 54% in integrated performance in processor tests. In the overclocked state, the difference in integrated performance between the Core i9-7900X @4.6GHz and Core i7-7740X @5GHz is already 60% in favor of the Core i9-7900X. The most significant advantage of the 10-core Core i9-7900X processor over the 4-core Core i7-7740X in video conversion tests (97% superiority without overclocking and 104% superiority with both processors overclocked), rendering (96% superiority without overclocking and 99 % when both processors are overclocked) and OCR (127% better without overclocking and 122% better when both processors are overclocked). In tests belonging to the «Scientific calculations» group and tests of the «Video editing and video content creation» group, the advantage of a 10-core processor is slightly more modest. But in the tests of the Digital Photo Processing group, the Core i9 processorThe -7900X has almost no advantage over the Core i7-7740X processor. Moreover, in the test based on the Adobe Photoshop CC 2015.5 application, the Core i7-7740X processor turns out to be more productive. That is, in this test, it is preferable to use a small number of fast cores than a large number of slow cores.

Power consumption results

Now let’s look at the results of measuring the power consumption of processors in tests of the iXBT Application Benchmark 2017 package.

Power consumption of the processor (power on the bus 12 V connector EPS12V) in watts is presented in the table:

Logical group of tests Core i9-7900X (2-channel memory mode) Core i9-7900X (4-channel memory mode) Core i9-7900X
@4. 6GHz
Core i7-7740X Core i7-7740X
@5 GHz
Video conversion
MediaCoder x64 143.8 143.7 213.4 83.0 118.7
HandBrake 0.10.5 154.0 154.2 232.8 88.4 125.6
POV Ray 3.7 196.4 194.6 231.9 78.4 110.7
LuxRender 1.6 x64 OpenCL 192.2 190.8 229.6 76.6 107.3
Вlender 2.77a 124.2 123.0 209.5 82.9 116.1
Video editing and video content creation
Adobe Premiere Pro CC 2015. 4 132.6 131.4 202.8 80.4 114.8
Magix Vegas Pro 13 152.4 155.9 192.7 70.8 91.8
Magix Movie Edit Pro 2016 Premium v. 137.3 135.4 205.6 71.7 101.1
Adobe After Effects CC 2015.3 122.1 121.3 190.7 58.2 82.7
Photodex ProShow Producer 8.0.3648 50.4 50.1 79.3 37.8 53.7
Digital Photo Processing
Adobe Photoshop CC 2015.5 50.4 50.0 101.4 41.0 58.0
Adobe Photoshop Lightroom CC 2015.6.1 69.6 68.5 121.5 48.5 67.8
PhaseOne Capture One Pro 9. 2.0.118 103.6 98.4 173.8 49.3 72.9
Abbyy FineReader 12 Professional 175.6 175.1 237.1 67.1 94.3
WinRAR 5.40 CPU 51.0 50.5 143.8 42.9 57.5
Scientific calculations
LAMMPS 64-bit 20160516 151.1 157.0 202.8 60.5 83.9
NAMD 2.11 196.5 197.1 236.2 74.6 105.4
FFTW 3.3.5 100.3 116.2 200.1 59.2 84.9
Mathworks Matlab 2016a 104.9 104. 3 201.7 51.3 71.9
Dassault SolidWorks 2016 SP0 Flow Simulation 100.6 100.0 179.2 56.4 78.3
File operation speed
WinRAR 5.40 Storage 16.6 15.8 64.8 11.2 14.3
UltraISO Premium Edition 16.1 15.3 66.9 10.6 15.0
Data copy speed 16.1 15.6 68.7 11.0 15.6

For convenience, we also present the power consumption results in the form of a diagram (averaged value for each logical group of tests).

If we talk about the Core i7-7740X processor with a declared TDP of 112 W, we can see that without overclocking, the power consumption of this processor does not exceed 90 W, and in the overclocked state, the highest power consumption value is 125 W. And in this case, the declared TDP is quite justified (although TDP and power consumption are not the same thing).

But for the Core i9-7900X processor, the declared TDP value of 140 W somehow does not correlate well with the real power consumption. Even without overclocking, the power consumption in some tests exceeds 190 W, and in overclocking it can already exceed 230 W. It is clear that with such a high power consumption, further overclocking of the processor is simply unrealistic. Firstly, with such a power it is very difficult to cool it (neither an air cooler nor an air cooler can cope with such power) and it will inevitably overheat. Secondly, there is a limit on the maximum value of the processor current, when exceeded, the protection is triggered.

As for dual-channel and quad-channel memory modes, the power consumption in these modes is almost the same.

As a reference, we also provide data on the total power consumption through the ATX and EPS12V connectors in watts:

Logical group of tests Core i9-7900X (2-channel memory mode) Core i9-7900X (4-channel memory mode) Core i9-7900X
@4. 6GHz
Core i7-7740X Core i7-7740X
@5 GHz
Video conversion
MediaCoder x64 179.3 182.1 253.8 113.7 149.8
HandBrake 0.10.5 190.7 190.8 270.3 118.7 156.0
POV Ray 3.7 229.9 228.1 265.3 104.8 137.7
LuxRender 1.6 x64 OpenCL 227.9 226.5 265.4 104.3 135.4
Вlender 2.77a 157.6 156.3 243.9 110.0 142.9
Video editing and video content creation
Adobe Premiere Pro CC 2015. 4 187.1 185.9 257.9 128.6 164.1
Magix Vegas Pro 13 207.3 210.9 247.5 118.3 139.4
Magix Movie Edit Pro 2016 Premium v. 174.3 172.4 243.9 101.3 132.4
Adobe After Effects CC 2015.3 155.2 154.3 224.4 84.1 110.1
Photodex ProShow Producer 8.0.3648 83.6 83.2 114.0 65.4 82.9
Digital Photo Processing
Adobe Photoshop CC 2015.5 95.9 95.7 151.5 85.5 104.6
Adobe Photoshop Lightroom CC 2015.6.1 103.9 102.8 156.9 78.2 99. 1
PhaseOne Capture One Pro 132.4 131.8 208.4 77.1 102.2
Text recognition
Abbyy FineReader 12 Professional 212.8 212.4 274.3 95.8 123.1
WinRAR 5.40 CPU 86.3 86.5 183.2 74.7 88.5
Scientific calculations
LAMMPS 64-bit 20160516 188.8 195.0 240.8 89.4 112.9
NAMD 2.11 233.7 234.0 273.5 102.4 133.3
FFTW 3.3.5 138.9 157.9 240.2 91.7 116. 4
Mathworks Matlab 2016a 137.6 137.4 235.5 77.5 98.5
Dassault SolidWorks 2016 SP0 Flow Simulation 134.0 133.0 215.1 84.1 106.4
File operation speed
WinRAR 5.40 Storage 47.7 46.6 96.8 36.3 39.4
UltraISO Premium Edition 47.0 45.9 98.8 35.8 39.9
Data copy speed 47.2 46.3 100.8 36.1 40.7
Game performance test results

In addition to testing the Core i9-7900X and Core i7-7740X processors using the iXBT Application Benchmark 2017 package, we also compared these processors in games using the iXBT Game Benchmark 2017 test package. We decided to do this testing exclusively for those users who naively believe that in games a 10-core processor can have an advantage over a 4-core one.

Of course, test results in games are determined primarily by the performance of the video card, not the processor. Therefore, it would be logical to assume that the Core i7-7740X and Core i9 processors-7900X with the same video card will show the same result in games. The only thing that may differ is the results in games with their settings set to the minimum quality. since in this mode the load on the video card is reduced and the load on the processor is increased. In fact, this is exactly what we wanted to test.

We didn’t overclock the processors in our gaming tests, and the Core i9-7900X only used dual-channel memory. In addition, we did not use all the tests from the iXBT Game Benchmark 2017 package: we excluded the games Dark Souls III and The Elder Scrolls V: Skyrim due to the fact that they have internal limitations of the maximum possible result of 60 FPS and the performance of the MSI GeForce video card The GTX 1070 Gaming X 8G is enough to achieve this result at any setting. Testing was carried out at a resolution of 2560×1440 with settings for maximum and minimum quality.

The results of testing at the maximum quality settings are as follows:

Game test Result, FPS
Core i7-7740X Core i9-7900X
World of Tanks 103.9 102.4
Battlefield 1 27.8 27.2
Deus Ex: Mankind Divided 10.6 10.6
Ashes of the Singularity 43.7 43.2
Far Cry Primal 65.1 63.8
Rise of the Tomb Raider 35.7 35.9
F1 2016 79.1 77.8
Hitman (2016) 33.4 33.1
Total War: Warhammer 37.1 36.5

For clarity, let’s also show the result in the diagram:

As expected, with the settings for maximum quality, the results are entirely determined by the performance of the video card and do not depend on the processor. Therefore, the 4-core Core i7-7740X and the 10-core Core i9-7900X show the same results in games.

Test results with minimum quality settings are as follows:

Play test Result, FPS
Core i7-7740X Core i9-7900X
World of Tanks 117.9 115.9
Battlefield 1 197.8 189.6
Deus Ex: Mankind Divided 85.5 87.4
Ashes of the Singularity 82.2 80.5
Far Cry Primal 102.9 96.3
Rise of the Tomb Raider 157.7 119.4
F1 2016 115.0 80.1
Hitman (2016) 151.2 129.5
Total War: Warhammer 151.6 150.3

Again, for clarity, we duplicate the results in the diagram:

As you can see, with the settings for the minimum quality in games such as Rise of the Tomb Raider, F1 2016 and Hitman (2016), the 4-core Core i7 processor demonstrates the advantage -7740X. In other games for the Core i7-7740X and Core i9-7900X processors, the result is approximately the same (also with a slight advantage of the Core i7-7740X processor). In general, the result is quite natural. Games don’t need many processor cores, and a few fast cores are better than a lot of slow ones.


In conclusion, let’s once again note the most important observations made by us during testing. If we talk about resource-intensive applications, then the 10-core Core i9-7900X outperforms the 4-core Core i7-7740X by 54% in terms of the integral performance result in processor tests. Overclocking the Core i9-7900X to 4.6 GHz allows you to increase performance by another 13.5%. However, such overclocking is accompanied by an increase in power consumption to more than 200 W, and under these conditions, the problem of processor cooling arises. Quad-channel memory mode in the Core i9 processor optionThe -7900X does not have a significant advantage over dual-channel mode — it is very difficult to find real-world applications that really need the bandwidth of 4 channels of DDR4 memory. And the last thing worth paying attention to is the fact that the 10-core Core i9-7900X is never a gaming processor, although sometimes they try to present it that way.

Overview of the Intel Core i9-7900X

Extreme tasks — an extreme processor. Core i9 linefrom Intel is the real embodiment of this truth. Prior to the advent of the Skylake-X architecture, 12, 14, 16, and 18-core CPUs were only available in the server class . But Intel decided that the frenzied power was also necessary for the mainstream segment (although the LGA 2066 platform cannot be called quite affordable), as a result, the ninth stones of Core were born.

The model called Intel Core i9-7900X is the youngest in the line of extreme nines for LGA 2066. In fact, this is a direct successor to the Intel Core i7-6950X Extreme Edition for LGA 2011-3, which also has 10 physical cores and 20 computational threads.

A distinctive feature of all Intel Core i9 is support for 44 PCI-E lines, which allow you to get the most out of NVIDIA SLI and AMD CrossFireX multi-graphic bundles; junior Core i7 models from the Skylake-X lineup offer 16 to 28 lanes.


14nm Intel Core i9 processor-7900X ten physical cores and 20 threads (Hyper-Threading technology; supports Intel SSE4.1, SSE4.2, AVX2 and AVX-512 instructions). Its nominal clock speed is 3300 MHz, but the most efficient core that the system automatically selects is capable of running at 4500 MHz (Intel Turbo Boost Max Technology 3.0).

The Intel Core i9-7900X has 13.75 MB of cache and a TDP of 140 W (actual thermal performance is still higher during rigorous testing). This CPU supports the DDR4-2666 RAM standard, the maximum capacity is 128 GB.

As we have already said, the stone reviewed by has 44 PCI-E lines, and we will try to understand whether the owner of several video cards needs these very lines to unlock the potential of top-end graphics accelerators. More on that below.

Intel Core i7-6950X Intel Core i9-7900X
Socket LGA 2011-3 LGA 2066
Cores/threads 10/20 10/20
Process 14 nm 14 nm
Rated frequency 3000 MHz 3300 MHz
Turbo frequency 3500 MHz 4300 MHz
L3 cache 25 MB 13. 75 MB
TDP 140W 140W
PCI-E lanes 40 44
Memory support DDR4-2400/2133 4ch DDR4-2666 4ch
Intel Hyper-Threading Yes Yes
Intel Turbo Boost 2.0 2.0
Cost $1730 $999

A few words about temperature readings. The manufacturer recommends removing heat from the Intel Core i9-7900X using a liquid cooling system, but this is not urgently necessary if you plan to use this CPU at its nominal value, that is, without manually increasing the clock frequency.

Intel Core i9-7900X under load (140W)

A powerful tower cooler with one 120-140 mm fan (for example, Arctic Freezer 33 Penta, Cryorig H7 Quad Lumi or Deepcool GAMMAXX GT) is enough to keep the temperature of the Intel Core i9-7900X within 60-70 degrees. Obviously, overclocking requires a completely different CO. Even an additional 100-200 MHz significantly affects the TDP, the temperature rises at a frantic pace, and here you cannot do without water . Five gigahertz without CBO will not be able to conquer.

The Intel X299 chipset platform is capable of operating with both dual-channel and quad-channel RAM. And we strongly recommend that you get 4 RAM modules if you plan to use the system productively and as efficiently as possible with Socket LGA 2066. The difference between 2 and 4 channels is significant (it’s about bandwidth), and it increases with increasing clock speed.

DDR4-3000, 2 channels

DDR4-3000, 4 channels

Test bench:

Motherboard — ASUS Prime X299-A
Cooling system — Cooler Master MasterLiquid Maker 92
RAM — Corsair Vengeance RGB DDR4-2666 (2×8 GB) + Kingston HyperX Fury DDR4-2666 (2×4 GB)
Graphics Cards — NVIDIA SLI, 2x ASUS ROG Strix GTX 1080
Storage — Plextor M8Se(Y) 512GB
Power Supply — Seasonic Prime Gold 1000W

Performance and Benchmarks

What to expect from a $1000 processor in the asset ten physical cores? Certainly impressive performance. This is what Intel Core i9 demonstrated-7900X in all tested benchmarks.

The Intel Core i9-7900X is strong where you need to quickly render/render a 3D scene or process a large amount of high-resolution digital content.

The reviewed toy is too good for home use, which is quite obvious; and even for professional tasks, this CPU is incredibly fast. It’s all about the presence of 10 physical cores that need to be used (otherwise, why would such a processor be in the system).

Not all existing programs (including those for calculating complex operations) are optimized for 20 computational threads. And a user who is thinking about purchasing an Intel Core i9-7900X needs to study compatibility points in advance . It is possible that for most applications with which to work, a 6 or 8-core CPU will suffice.

Note that the power of one core in the Intel Core i9-7900X is neither higher nor lower than, for example, that of the Intel Core i5-8600K, and this fact once again proves that for many tasks that an ordinary user faces daily , a 2 or 4-core Core i3 or Core i5 processor is sufficient.

The Intel Core i9-7900X is strong where you need to quickly render/calculate a 3D scene or process a large amount of high-resolution digital content. Such a processor mainly saves time, this is its key feature.

In a professional environment, people are faced with operations that take dozens of hours, and sometimes more than one day. Intel Core i9-7900X is able to reduce time costs.

Support for 44 PCI-E lanes

Perhaps the only technical feature of the Intel Core i9-7900X that may be of interest to a gamer is support for 44 PCI-E lanes. This is the current maximum. Thanks to this functionality, a pair of graphics accelerators is able to work in the system at full x16 speeds (x16 + x16), and three adapters — x16 + x16 + x8. But does it make sense?

The Intel Core i9-7900X is a great CPU for streamlined processes and core tasks where 10 cores are really in demand.

We have done research to find the answer to this curious question. The reviewed processor, a pair of ASUS ROG Strix GTX 1080 and Intel Core i7-7800X video cards with support for 28 lines took part in it (for comparison, the x16 + x16 and x16 + x8 formats).

A full report on the experiment is published in the corresponding article about NVIDIA SLI. In this article, we will only say that the increase from the x16 + x16 mode is noticeable only in some optimized games, of which there are not so many now, for example, in Ghost Recon Wildlands, GTA 5 and Rainbow Six Siege.

The difference between x16+x16 and x16+x8 is minimal (several extra fps in favor of a more than wide channel) and, again, is noticeable only in a few game projects (3DMark did not react to additional PCI-E lanes in any way).



For high-definition games, it is better to choose one powerful accelerator. Buying an Intel Core i9-7900X for the sake of 44 PCI-E lanes is definitely not worth it, we have personally seen this.


The Intel Core i9-7900X is a great processor for extreme testing, just like any stone from of the ninth Core line. But on air it will not be possible to achieve a worthwhile result, due to the high TDP.

It is not difficult to increase the clock frequency on this CPU (there is an open multiplier here, and the voltage of the automatic throws on its own, exactly as much as is required for stable operation), it is much more difficult to remove heat.

4600 MHz

4800 MHz

With the help of weak dropsy Cooler Master MasterLiquid Maker 92 we were able to overclock the Intel Core i9-7900X to 4800 MHz, but without a stable result. At a more modest 4600 MHz (all 10 cores operated at this frequency), the operating temperature exceeded 90 degrees, which is not the norm, throttling took place.

For a good and stable result, a full-scale CBO is required, with its help it will be possible to conquer 5 GHz and higher, and the performance in this case will be enormous (and TDP will go far beyond 200-300 W).

The effect of overclocking the Intel Core i9-7900X


The Intel Core i9-7900X is a great CPU for streamlined processes and core workloads where 10 cores are really needed. This is not a gamer’s toy (44 PCI-E lanes for and NVIDIA SLI tandems are useless due to software limitations that unoptimized designs are).

Before us stone server level with a high clock speed, focused on extreme desktop. Core i9The -7900X saves time and delivers massive hardware resources where they are needed. Recommended.

Keywords: Intel

Review and Benchmark Intel Core i9-7900X is a worthy answer to AMD Threadripper HEDT processors

starting with the i9-7900X. The high-end desktop (HEDT) platform occupies the buffer space between productive desktops and serious workstations. For a decade, Intel has turned its attention to the CPU segment, which has more features than standard desktop options. Such chips typically included more cores, wider memory interfaces, more PCI-Express lanes per platform, and so on. Consumers know roughly what to expect when buying a HEDT-class processor, as the segment started in 2008 with the Core i7 «Nehalem» series along with the X58 Express chipset.

A panic reaction to AMD’s Ryzen 5 and Ryzen 7 processors, offering HEDT multi-threaded performance in the mainstream segment that 7th generation «Kaby Lake» chips could not keep up with, was the launch of Intel’s Core X family with 4-core Core i5-7640X and Core i7-7740X, 6-core i7-7800X plus 8-core i7-7820X. Core i5-7640X and i7-7740X — turned out to be only HEDT; ordinary desktop mainstream processors, and, as the review of the i5-7640X showed, they can not be classified as high-performance. The i7-7800X and i7-7820X, on the other hand, offer far more cores and a wider memory interface, but again show a dismal amount of PCI-Express lanes. Reducing the multi-GPU in a system isn’t really a critical aspect for content creators, but some pros would definitely put the extra PCIe lanes to good use, like 4K multi-stream video capture adapters, multiple NVMe SSDs, etc.

The newly baptized Core i9 family is exactly where Intel’s latest line of HEDT processors starts, as they meet the three main platform goals: many cores, more memory channels and more PCIe lanes (now definitely enough for two x16 video cards) , and as Core-counts are approaching double digits, Intel is pricing these chips past the $1,000 mark. Core i9-7900X is a $999 ten-core chip, Intel’s pricing logic could be as follows, its spiritual predecessor Core i7-6900X was also a 10-core CPU that was priced at $1,000.


Core i9-7900X is built on a new giant die based on the Skylake micro-architecture called «Skylake-X». It implements the biggest change in the way Intel builds processors, as «Nehalem» is called Mesh Topology. The chip overcomes the limitations of the old ring bus by tying together a large number of processor cores without the performance penalty that comes with latency. It also implements an equally significant change to the cache hierarchy, with faster, dedicated L2 cache being quadrupled and L3 cache rather modest.

In this review, we take a look at the performance of the Core i9-7900X and compare it with the Ryzen Threadripper 1950X against AMD’s main competitor.


  1. Closer
  2. Architecture
  3. Test configurations
  4. Tests Arithmetic CPU
  5. Media encoding
  6. Working and Compression
  7. Antivirus, Java and Database performance
  8. Rendering and Modeling
  9. Web performance
  10. Game tests: 720p
  11. Game Tests: Part 1
  12. Game Tests: Part 2
  13. Min. FPS: Part 1
  14. Min. FPS: Part 2
  15. Power input
  16. Overclocking
  17. Performance summary
  18. Rating and review


Price Cores /
Base frequency Max.
TDP Architecture Process Socket
Ryzen 7 1700X 360 $ 8 / 16 3.4 GHz 3.8 GHz 16 MB 95W Zen 14 nm AM4
Core i7-8700K $380 6 / 12 3.7 GHz 4.7 GHz 12 MB 95 W Coffee Lake 14 nm LGA 1151
Core i7-7800X $380 6 / 12 3.5 GHz 4.0 GHz 8.25 MB 140 W Skylake 14 nm LGA 2066
Ryzen 7 1800X $450 8 / 16 3. 6 GHz 4.0 GHz 16 MB 95W Zen 14 nm AM4
Core i7-7820X 600 $ 8 / 16 3.6 GHz 4.5 GHz 11 MB 140 W Skylake 14 nm LGA 2066
Threadripper 1920X $650 12 / 24 3.5 GHz 4.0 GHz 32 MB 180 W Zen 14 nm TR4
Threadripper 1950X $800 16 / 32 3.4 GHz 4.0 GHz 32 MB 180 W Zen 14 nm TR4
Core i9-7900X 970 $ 10 / 20 3.3 GHz 4.4 GHz 13.75 MB 140 W Skylake 14 nm LGA 2066
Core i9-7920X 1200 $ 12 / 24 2. 9 GHz 4.3 GHz 16.5 MB 140 W Skylake 14 nm LGA 2066
Core i9-7940X 1400 $ 14 / 28 3.1 GHz 4.3 GHz 18.25 MB 165 W Skylake 14 nm LGA 2066
Core i9-7960X 1700 $ 16 / 32 2.8 GHz 4.2 GHz 22 MB 165 W Skylake 14 nm LGA 2066

Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Entry marks:
#Core X#HEDT#Intel X299#LGA2066#Skylake#Reviews#Intel



Intel Core i9-7900X — 65 secret facts, review, specifications, reviews.

Top specifications and features

  • PassMark CPU score
  • Cinebench score21.5 (single)
  • Heat dissipation (TDP)
  • Technological process
  • Number of Cores

PassMark CPU

Intel Core i9-7900X score:
Best score:

Test results of

Intel Core i9-7900X:
Best score:


Intel Core i9-7900X:
Best score:


Intel Core i9-7900X:
Best score:

Memory Specification

Intel Core i9-7900X:
Best score:


Intel Core i9-7900X processor running at 3. 3 Hz. At the same time, the maximum frequency in Boost mode reaches 4.3 Hz. 10 cores available. The L1 cache is 320 KB, L2 10 MB and L3 20 MB. Power consumption at peak times can reach 140 watts.

The maximum number of threads that the Intel Core i9-7900X can work with is 20.

The Intel Core i9-7900X works on the 14 nm architecture.

Regarding memory specification. The Intel Core i9-7900X processor supports DDR4. The frequency of RAM is 2666. The maximum supported volume is 128 MB. The maximum memory bandwidth is 85. The number of supported memory channels is 4.

Now about the Intel Core i9-7900X tests. According to PassMark, the processor scored 22407 of the possible points. Based on analysis of over 4,000 processors, Intel Core i9-7900X ranked 111th in the Top 10.

Why the Intel Core i9-7900X is better than others

  • PassMark CPU score 22407 . This parameter is higher than that of 51%
  • Cinebench21.5 score (single) 25 . This parameter is higher than that of 13%
  • Process technology 14 nm. This parameter is lower than 89%
  • Number of cores 10 . This parameter is higher than 85%
  • Number of threads 20 . This parameter is higher than that of 74%
  • L2 cache size 10 MB. This parameter is higher than 70%
  • L1 cache size 320 KB. This parameter is higher than that of 43%
  • Thermal Dissipation (TDP) 140 W. This parameter is higher than 91%

Overview Intel Core i9-7900X

Test results



Memory specification

Interfaces and communications

Main characteristics

Intel Core i9-7900X Review: Highlights

PassMark CPU score

The PassMark test considers read speed, write speed, and seek time when testing SSD performance.
Show all


max 89379

Average: 6033. 5


Cinebench21.5 score (single)

A benchmark that measures processor performance using a thread of execution.


max 51

Average: 5.6


3DMark06 test score


max 18628

Average: 3892.6


Test score Cinebench R11.5 /64bit (Multi-Core)


max 45.3622

Average: 5.3


Cinebench R15 test score (Multi-Core)


max 4614

Average: 638.4


Cinebench R15 test score (Single-Core)


max 276

Average: 128. 5




Support for Intel Optane memory


Number of AVX-512 FMA modules


Mean: 1.8


Function Execute override bit


Number of threads

The more threads, the higher the performance of the processor, and it will be able to perform several tasks at the same time.
Show all


max 256

Average: 10.7


L1 cache size

Large amount of L1 memory accelerates results in CPU and system performance settings
Show all


max 4608

Average: 299. 3 KB


L2 Cache Size

L2 cache with large scratchpad memory to increase processor speed and overall system performance.
Show all


max 512

Average: 4.5 MB


L3 cache size

Large amount of L3 memory accelerates results in CPU and system performance settings
Show all


max 768

Average: 16.3 MB


Maximum Turbo Clock Speed ​​

When the processor speed drops below its limit, it can jump to a higher clock speed to improve performance.
Show all


max 5.5

Average: 3. 2 GHz


Number of cores


max 72

Mean: 5.8


Processor base clock speed


max 4.7

Average: 2.5 GHz


Max. number of PCI Express lanes


max 64

Average: 22.7


Unlocked CPU multiplier

Some processors have an unlocked multiplier, thanks to which they work faster and improve the quality in games and other applications.
Show all


Turbo Boost Technology

Turbo Boost is a technology that allows the processor to operate at a frequency higher than the maximum. This increases its productivity (including when performing complex tasks)
Show all


Mean: 1.9


Turbo Boost Max 3.0


Number of PCI-Express lanes


Max. number of processors in the configuration


Mean: 1.3


DDR version


Mean: 3.5


Max. memory bandwidth

This is the rate at which the device stores or reads information.


max 352

Average: 41.4 GB/s


Memory frequency

The RAM can be faster to improve system performance.
Show all


max 4800

Average: 2106.2 MHz

4800 MHz

Max. number of memory channels


max 16

Mean: 2.9


Max. memory size

Largest RAM memory.


max 6000

Average: 404.4 GB


System bus frequency

Data is transferred between computer components and other devices via the bus.
Show all

8 GT/s

max 1600

Average: 156.1 GT/s

1600 GT/s

ECC memory support

Memory debugging code is used when it is necessary to avoid data corruption during scientific computing or server startup. It finds possible errors and repairs data corruption.
Show all


Enhanced SpeedStep (EIST)


Intel® AES-NI Commands

AES is needed to speed up encryption and decryption.


Hyper-Threading Technology

Many Intel processors use state-of-the-art hyper-threading technology. Thus, each processor core works simultaneously on two threads, which significantly increases performance. Most processors work on the principle: one thread per core, therefore, their performance is lower.
Show all



AVX allows you to increase the speed of calculations in multimedia, financial and scientific applications, it also improves the performance of Linux RAID.
Show all


Version sse

Allows you to speed up multimedia tasks (such as adjusting the volume of the sound). Each subsequent version has a number of improvements
Show all


max 4.2

Average: 4.1










AMD Virtualization Technology


Process technology

The small size of the semiconductor means it is a new generation chip.

14 nm

Average: 36.8 nm


Heat Dissipation (TDP)

The Heat Dissipation Requirements (TDP) is the maximum amount of energy that can be dissipated by the cooling system. The lower the TDP, the less power will be consumed.
Show all


Average: 67.6 W


PCI Express Revision


Mean: 2.9




Release date


Embedded options available


Cooling System Specifications

PCG 2017X

Supports 64-bit system

A 64-bit system, unlike a 32-bit system, can support more than 4 GB of RAM. This increases productivity. It also allows you to run 64-bit applications.
Show all


Maximum Processor Temperature

A reset may occur if the maximum temperature at which the processor operates is exceeded.
Show all


max 110

Average value: 96 °C


Code name





How many PCIe lanes


How much RAM does the Intel Core i9-7900X support?

Intel Core i9-7900X supports 128 GB.

How fast is the Intel Core i9-7900X 5600X?

The processor runs at 3.3 GHz.

How many cores does the Intel Core i9-7900X have?

10 cores.

Does the Intel Core i9-7900X support ECC memory?


What is the socket of Intel Core i9-7900X

To install Intel Core i9-7900X is used by FCLGA2066.

Is the Intel Core i9-7900X a 64-bit processor


What architecture does the Intel Core i9-7900X use?

The Intel Core i9-7900X is based on the Skylake architecture.

Is the Intel Core i9-7900X multiplier unlocked?


How does the Intel Core i9-7900X processor perform in benchmarks?

According to PassMark, the Intel Core i9-7900X scored 22407 points.

What is the frequency of the Intel Core i9 processor-7900X?

Intel Core i9-7900X processor running at 3. 3 Hz.

What is the maximum frequency of the Intel Core i9-7900X?

In this case, the maximum frequency in Boost mode reaches 4.3 Hz.

How much cache is the Intel Core i9-7900X?

L1 cache is 320 KB, L2 10 MB and L3 20 MB.

How many watts does the Intel Core i9-7900X consume?

Power consumption at peak times can be up to 140 watts.

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Intel Core i9-7900X — processor overview. Tests and specifications

The Intel Core i9-7900X processor is based on 14 nm process technology and the Skylake-X architecture. The base clock is 3.30 GHz and the maximum turbo clock is 4.30 GHz. Intel Core i9-7900X contains 10 processor cores. To make the right choice for upgrading your computer, check out the detailed specifications and test results. Please check your motherboard socket compatibility before choosing.

0. 0
From 1
Hitesti Score

TOP 10 processors

Most popular on the site

Intel Celeron N4020
2x 1.10 GHz (2.80 GHz)

AMD Ryzen 5 5500U
6x 2.10 GHz (4.00 GHz) HT

Intel Celeron J4125
4x 2.00 GHz (2.70 GHz)

AMD Ryzen 3 3250U
2x 2. 60 GHz (3.50 GHz) HT

AMD Ryzen 7 5700U
8x 1.80 GHz (4.30 GHz) HT

AMD Athlon Silver 3050U
2x 2.30 GHz (3.20 GHz)

Intel Core i3-1115G4
2x 1.70 GHz (4.10 GHz) HT

Intel Core i5-1135G7
4x 2. 40 GHz (4.00 GHz) HT

AMD Ryzen 5 4600G
6x 3.70 GHz (4.20 GHz) HT

Intel Celeron N4500
2x 1.10 GHz (2.90 GHz)

Buy here:


General information

Intel Core i9-7900X base and maximum clock speed, number of processor cores and threads. The more the better (marked in green).

CPU cores, base and turbo speeds

The overall performance of a processor can be easily determined based on its number of cores and threads, as well as its standard and turbo clock speeds. The more GHz, cores and L2-L3 cache a processor has, the better. Please note that high specs require a powerful cooling system and a quality chipset (check the VRM on the motherboard).

Clock frequency: 3.30 GHz Number of cores: 10
Turbo (1 core): 4.30 GHz Number of threads: 20
Hyper trading: Yes Acceleration: Yes
Turbo (10 Cores): 4. 00 GHz

Internal graphics

Some manufacturers (most often Intel) supplement processors with graphics chips, this solution is especially popular in laptops, but ineffective in workstations and gaming stations. The higher the clock speed of the video card and the more memory on board, the better.

GPU (Turbo): No turbo Maximum memory:

Hardware codec support

Here we are dealing with specifications that are used by some processor manufacturers. These figures are mostly technical and can be disregarded for comparative purposes.

h364: No.
h365 8bit: No.
h365 10bit: No.
VP8: No.
VP9: No.
VC-1: No.
AVC: No.

RAM and PCIe

These are the memory standards supported by processors. The higher the standard and clock frequency with the amount of RAM, the better the performance and speed of the processor. It is also worth considering the possibility of memory operation in multichannel mode.

Memory type: DDR4-2666 Memory channels: 4
ECC: No PCIe version: 3. 0
PCIe lanes: 44


Support for data encryption


Thermal management and TDP

TDP: 140W Maximum temperature:
Maximum TDP: TDP down:

Technical details

These are key parameters that will help you determine which processor is best. Pay special attention to the release date, the technological aspects of the manufacturing process (measured in nanometers) and the third level (L3) cache.

L3-Cache: 14.00MB Technology: 14nm
Architecture: Skylake-X Virtualization: VT-x, VT-d
Socket: LGA 2066 Release date: Q2/2017
Price: ca. 989 $

Devices compatible with this processor

You probably already know which devices use processors. It can be a desktop computer or a laptop.

Used in: Unknown

This synthetic benchmark will help you determine the actual processing power of a single CPU core. Cinebench R11.5 is based on MAXON CINEMA 4D and uses various test scenarios

Intel Core i5-7640X
4x 4. 00 GHz (4.20 GHz) HT

Intel Core i5-7600K
4x 3.80 GHz (4.20 GHz)

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

Intel Xeon Gold 6146
12x 3.20 GHz (4.20 GHz) HT

Intel Xeon Gold 6144
8x 3. 50 GHz (4.20 GHz) HT

Cinebench R11.5 performs simultaneous cross-platform tests on all processor cores. Running realistic 3D scenes, this benchmark will unleash the full potential of your single-core Intel or AMD 9 processor0003

Intel Xeon E5-2680 v4
14x 2.40 GHz (3.30 GHz) HT

Intel Xeon Gold 6136
12x 3.00 GHz (3.70 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

Intel Xeon E5-2697v3
14x 2.60 GHz (3.60 GHz) HT

Intel Xeon Platinum 8153
16x 2.00 GHz (2.80 GHz) HT

The latter is used to create 3D models and shapes. Cinebench R15 is used to benchmark the performance of single core processors. Hyperthreading capability is not taken into account. It is an updated version of Cinebench 11.5. Like all new versions, the updated benchmark is based on Cinema 4 Suite


Intel Core i5-10400
6×2. 90 GHz (4.30 GHz) HT

Intel Core i7-8557U
4x 1.70 GHz (4.50 GHz) HT

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

Intel Xeon E3-1280v6
4×3.90 GHz (4.20 GHz) HT

Intel Xeon E3-1275 v6
4x 3. 80 GHz (4.20 GHz) HT

Cinebench R15 can be used to test the performance of multi-core processors. The test produces accurate and reliable results. This benchmark is an updated version of Cinebench 11.5, which is based on Cinema 4 Suite soft.

Intel Xeon Gold 6136
12x 3.00 GHz (3.70 GHz) HT

Intel Core i9-9900KS
8x 4.00 GHz (5.00 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

AMD Epyc 7351P
16x 2.40 GHz (2.90 GHz) HT

AMD Epyc 7351
16x 2.40 GHz (2.90 GHz) HT

Cinebench R20 is based on Cinema 4 Suite. This is software used to create 3D shapes. The benchmark runs in single-core mode without considering the possibility of hyper-threading.

AMD Ryzen 3 PRO 4350GE
4x 3. 50 GHz (4.00 GHz) HT

AMD Ryzen 3 4200G
4x 3.80 GHz (4.10 GHz) HT

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

Intel Core i7-10710U
6x 1.10 GHz (4.70 GHz) HT

Intel Core i9-9980XE
18x 3. 00 GHz (4.50 GHz) HT

This is a new version of the benchmark based on Cinebench R15 (both versions are based on Cinema 4, the most popular 3D modeling software). Cinebench R20 is used for benchmark tests of multi-core processor performance and hyper-threading capability.

Intel Core i7-10700KF
8x 3.80 GHz (5.10 GHz) HT

Intel Core i7-10700K
8x 3.80 GHz (5.10 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

Intel Xeon Platinum 8160M
24x 2.10 GHz (3.70 GHz) HT

Intel Core i9-9900KS
8x 4.00 GHz (5.00 GHz) HT

Cinebench R23 is a new version of the most popular single-core CPU rendering benchmark Cinebench. We have results for all 9 modern processors0003

AMD Ryzen 7 4800H
8x 2. 90 GHz (4.20 GHz) HT

AMD Ryzen Threadripper Pro 3995WX
64x 2.70 GHz (4.20 GHz) HT

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

AMD Ryzen 5 4600G
6x 3.70 GHz (4.20 GHz) HT

AMD Ryzen 5 PRO 4650GE
6x 3. 30 GHz (4.20 GHz) HT

Cinebench R23 is a new version of the most popular multi-core CPU rendering benchmark, Cinebench. We have results for all modern


Intel Core i7-11700KF
8x 3.60 GHz (5.00 GHz) HT

Intel Core i7-11700K
8x 3.40 GHz (5.00 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

Apple M1X
12x 3.35 GHz (No turbo)

AMD Ryzen 7 PRO 5750G
8x 3.80 GHz (4.60 GHz) HT

Geekbench 3 is a benchmark for 64-bit Intel and AMD processors. It uses a new power rating system for a single processor core. This software simulates real scenarios for accurate results

Intel Core i5-9500
6x 3. 00 GHz (4.40 GHz)

Intel Core i7-10510U
4x 1.80 GHz (4.80 GHz) HT

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

Intel Core i7-8850H
6x 2.60 GHz (4.30 GHz) HT

AMD Ryzen 7 2700X
8x 3. 70 GHz (4.30 GHz) HT

Geekbench 3 supports multi-core AMD and Intel processors. Based on MAXON CINEMA 4D, it allows you to get the real comparative potential of the processor

Intel Xeon Gold 6132
14x 2.60 GHz (3.70 GHz) HT

Intel Xeon Gold 6136
12x 3.00 GHz (3.70 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

Intel Xeon E5-2690v3
12x 2.60 GHz (3.50 GHz) HT

Intel Xeon Platinum 8153
16x 2.00 GHz (2.80 GHz) HT

Geekbench 5 is the latest software. Completely new algorithms provide fairly accurate test results for single-core processors.

Intel Core i9-9900X
10x 3. 50 GHz (4.50 GHz) HT

AMD Ryzen 5 3500
6x 3.60 GHz (4.10 GHz)

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

Intel Core i5-8600
6x 3.10 GHz (4.20 GHz)

Intel Core i9-9880H
8x 2. 30 GHz (4.80 GHz) HT

Geekbench 5 benchmark results for memory performance and multi-core processor speed. This takes into account the ability to hyperthreading.

AMD Ryzen Threadripper 1950X
16x 3.40 GHz (4.00 GHz) HT

Intel Xeon E5-2695v3
14x 2.30 GHz (3.30 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

AMD Ryzen 7 5700G
8x 3.80 GHz (4.50 GHz) HT

Intel Core i7-11700
8×2.90 GHz (4.40 GHz) HT

We use the Blender benchmark to monitor CPU performance. Test results show how fast the device performs when performing multiprocessing tasks

AMD Ryzen Threadripper 2920X
12x 3. 50 GHz (4.30 GHz) HT

Intel Core i9-9920X
12x 3.50 GHz (4.50 GHz) HT

Intel Core i9-7900X
10x 3.30 GHz (4.30 GHz) HT

Intel Core i9-10900X
10x 3.70 GHz (4.70 GHz) HT

Intel Core i9-10850K
10x 3. 60 GHz (5.20 GHz) HT

It tests all and general CPU performance (math calculations, compression and decompression speed, 2D&3D graphics tests). Please note that data may differ from actual situations.

AMD Ryzen Threadripper 1950X
16x 3.40 GHz (4.00 GHz) HT

Intel Xeon W-2155
10x 3.30 GHz (4.50 GHz) HT

Intel Core i9-7900X
10x 3. 30 GHz (4.30 GHz) HT

Intel Xeon E5-2698 v4
20x 2.20 GHz (3.60 GHz) HT

Intel Core i9-9820X
10x 3.30 GHz (4.20 GHz) HT

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Intel Core i9-7900X Review — Computer Geek

Whether it’s the car market, the fresh fruit market, or the world’s most advanced silicon, competition is important. In the computing world, we haven’t seen a better sign of this than the high-performance desktop market over the past few years. The AMD FX processor line, which debuted with the AMD FX-8150 back in 2011, was serviceable, but it never really offered Intel any real competition above the Core i5 level. With this, Intel was able to shift its focus to energy efficiency for the larger notebook market without having to defend its flanks. And as a result, especially in the last few years, the increase in computing performance has been modest (to put it mildly) from one generation of chips to another. Of course, at Computex 2016, Intel took a step forward with the release of the 10-core Core i7-6950X Extreme Edition ($628.90 on Amazon), but this chip cost an incredible $1600+.

But then, in early 2017, AMD burst onto the HPC scene again with its Ryzen processors, led by the top-end AMD Ryzen 7 1800X. Ryzen chips are much more efficient and powerful than previous generation FX components. And they deliver up to 16 compute threads of performance at prices that are sometimes only half that of similarly-equipped Intel competitors. Not wanting to stop there, AMD recently announced that it will soon offer 16 A 32-core processor as part of Threadripper’s upcoming line of enthusiast chips that the company says we should see this summer.

This brings us to today, where, at least in part, in response to this new competition in the enthusiast space, Intel is offering more details on its line of Core i9 processors, which will have between 10 and 18 cores. We haven’t yet received a top-end Core i9-7980XE. Intel says the chip won’t arrive until October. But below we’ll look at the 10-core Core i9-7900X. new Intel Core X family, it will require a new motherboard with a new LGA 2066 socket.

But, most importantly, in terms of compute value per dollar, the Core i9-7900X replaces last year’s 10-core Core i7-6950X Extreme Edition chip, which cost around $1,700, with a more reasonable (though still certainly , expensive) ) ​​999 dollars.

The real test for this chip for now will be comparing it to AMD’s top octa-core Ryzen 7 1800X processor. This chip costs a couple of cores less. 10-core Core i9 processorThe .Ryzen 7 1800X retailed for just $440 when we wrote about it in mid-June 2017.

Meet the New Core X Series

Leading the Core i9-7980XE, which will be able to handle up to 36 threads simultaneously when it debuts, the new Core X-Series chips go beyond what we’ve seen in any Extreme Edition processors. on our test benches over the last decade. The Core i9-7980XE is, in fact, the first processor to deliver more than teraflops of compute performance for consumer computing. That alone is reason to take a step back and say wow.

Along with the highest-end chips, Intel will also introduce a number of «lower» processors. Core i7 and Core i5 processors for the new platform, which also uses a new socket, dubbed «LGA 2066». Here is a list of the company’s new chips received directly from Intel. Note that Intel is keeping many of the details of the top four Core i9 chips under wraps for now, so all the dashes below.

Now if you look at the prices, you will notice that the top 18-core Core i9The -7980XE costs an impressive $1999. (At least that’s for 1000 units, which is how Intel has long listed prices for its highest-end processors, although retail prices are usually about the same). It’s clear that Intel isn’t too worried about AMD being at the top of the stack. (And keep in mind, at the time of this writing, we still don’t know how AMD will price its competing Threadripper chips.)

But if you look at the 10-core Core i9-7900X we’re reviewing here, you’ll notice , that at a price of 9At $99, it costs about $700 less than the previous generation Core i7-6950X. So while prices are still quite high, there is clearly progress in terms of threads per dollar. And Intel offers a lot more options at the high end. level. So there’s no need to approach (or even approach) the $2,000 range unless you absolutely need all the streams you can get. More choice is good, and it’s likely that Intel has it, but at least in part because of what AMD has done this year.

As such, the octa-core, 12-thread Core i7-7820K, which is likely to be the most direct competitor to AMD’s top Ryzen 7 chip, costs $599. That’s about $150 more than the current price of the Ryzen 7 1800X. but much more affordable than the $1,000 price tag for the previous-gen Core i7-6900K octa-core processor ($628.90 on Amazon) (opens in a new window). Clearly, Intel is trying to recover some of its core cost per dollar over AMD while maintaining some price premium over its desktop processor competitor. This is not an all-out price war.

Another interesting difference from the Core X launch is that the company is using two chip architectures (or at least two generations of silicon) for its enthusiast platform at the same time for the first time. The highest-end chips here are based on 6th grade silicon. the «Skylake» generations, while the ones at the bottom of the diagram above, the Core i7-7740X and Core i5-7640X, are actually based on the 7th generation «Kaby Lake» architecture. the same as what you’ll find in Intel’s current top-of-the-line mainstream processor, the Core i7-7700K.

This is important for several reasons, but in terms of features it means that Kaby Lake chips will support 4K HEVC encode and decode at 10-bit depth as well as VP9 decode. What does that mean in non-geekish parlance? You will need a chip from the Kaby Lake line (or later) if you want your system to support streaming 4K content from most major video outputs, or if you plan to plug in a 4K Blu-Ray drive at some point. A Skylake chip (even an 18-core beast) will not cope with such content.

We’ll have reviews of the Core i7-7740X and Core i5-7640X in the coming days. So stay tuned if you’re intrigued by the Core X platform but looking for something a little more affordable.

CPU PCI Express Lanes & Chipset

Another major new issue that’s coming up with Core X has to do with PCI Express (PCIe) lanes, which you can think of as a backbone that shuffles bandwidth-hungry data between the CPU and stuff like that. like graphics cards and fast NVMe SSDs. Intel’s enthusiast platform has long offered more lanes directly to the CPU than «smaller» chips like the Core i7-7700K. For example, the Core i7-69The latest generation 50X has 40 PCI Express lanes, while the Core i7-7700K has 16 in total. .

Now that the Core X platform spans two generations of silicon and ranges from a somewhat modest four-thread Core i5 chip to an (ultimately) $2,000 36-thread monster chip, the number of PCIe lanes on the platform is much more complicated. at least two «entry-level» Core i5 and i7 chips (which we just mentioned above) will offer 16 lines, just like their counterparts on more popular platforms (like the Core i7-7700K). Taking the stack up to the more mid-range of this high-end platform, the Core i7-7800X and Core i7-7820X will offer 28 PCI Express lanes, while the Core i9The -7900X we’re reviewing here will offer 44 lanes. The extra four lanes over the previous generation are ostensibly designed to allow builders to have the bandwidth to use the new Intel Optane Memory caching drives and eventually full-size Optane drives. Interesting that Intel is keeping the number of PCI Express lanes available on its upcoming highest-end chips a secret for now. But it’s safe to say they will have 44 lanes or more.

If you’re wondering what you (or say, someone who won the computer hardware lottery) could actually do with all those PCI Express lanes on the CPU, the Core X introduces another feature that might be quite demanding bandwidth: VROC.

Virtual RAID on CPU (VROC) allows you to simultaneously run multiple PCI Express/NVMe drives in the RAID option of your choice directly through the CPU. Technically, this feature supports up to 20 drives clustered in a way that provides up to a theoretical throughput of up to 128 GB per second (and yes, that’s big gigabytes).

Before we get into the details of VROC, please note that Intel has yet to officially announce the details of VROC. Everything we’ve learned about this feature has come from motherboard manufacturers at Computex 2017. So take it with a grain of salt and know that things may change when Intel releases final official specs and details about this feature.

Previously, on the consumer side of the CPU fence, you needed a hardware RAID card to do something like a VROC setup. But as we’ll see, there are quite a few caveats here.

First, you’ll need one of the two hardware dongles attached to your X299-based motherboard to run drives in any configuration other than RAID 0 (striping). And we were told these keys would cost $100 or $200 respectively, depending on what type of RAID you plan to use. This is likely an attempt by Intel to keep enterprise customers from saving money by using consumer boards and processors to perform tasks designed for server class boards and Xeon processors.

Second, you’ll need one of the Skylake X chips (like the Core i9-7900X we’re reviewing here) to use VROC. Kaby Lake X chips lack the PCI Express bandwidth to make this setup possible.

The final VROC caveat is a big one. At least for now, in order for your VROC RAID drive to be bootable, you need to run the array on Intel SSDs. Considering Samsung consumer drives (such as the Samsung SSD 960 Pro) are the fastest, having to choose Intel drives seems counterintuitive if you’re going down that path (and spending so much money) to get the fastest results. storage speed. Hopefully a future feature update will allow loading non-Intel drives in a VROC setup.

The last feature of these new chips is an update to the company’s Turbo Boost Max technology, which debuted in previous generation Broadwell-E chips such as the Core i7-6950X Extreme Edition. Now, instead of the chip being able to determine which its multiple cores can run at maximum clock speed, and prioritize those cores for certain tasks, Core X chips can choose two cores that get Turbo Boost Max processing.

Like the Extended Frequency Range (XFR) feature found in AMD Ryzen chips (at least those ending in «X»), this is a good idea in theory. But it probably means minimal noticeable benefit at best. in overall performance. Getting a couple hundred extra megahertz in short-term bursts from one or two cores on a multi-chip chip won’t change how fast your system runs — unless perhaps the «feel» you’re talking about comes from watching the sky . high but esoteric test scores.

Along with the new chips and the new LGA 2066 socket, Intel will also offer a new X299 chipset to support all of this.

The chipset has up to 24 PCI Express lanes dangling from the board (remember, this is in addition to the 44 lanes on the processors that plug into the motherboard’s X299 socket). This is a big jump from the eight lanes available on the previous generation X99 chipset, and means X299 boards will support more SATA ports, USB 3 ports, and fast M.2 storage natively. If you want to connect all of these devices to your powerful PC,X299 should serve you well, but note that AMD Threadripper chips will reportedly have even crazier 64 PCI Express lanes on the chips themselves. (And not just high-end chips, but all of them.) As long as Threadripper’s performance can at least keep up, it looks like Intel will have strong competition in that high-end enthusiast space as well.

Another problem with X299 and Core X is memory. While Skylake X chips support DDR4 memory running in quad-channel mode up to 2666 MHz (and higher when overclocked), lower-end Kaby Lake X processors run in dual-channel mode. mode. This means that X29 motherboards9 will need to support both settings and you will have to set up your RAM differently depending on which chip you have installed.

This also means that the amount of RAM the board will support will depend on which chip you have installed. For example, here are the RAM specifications for the Asus Prime X299-Deluxe(Opens in a new window) motherboard we use as testbed for Core X reviews…

So the Core X and X299 chipset seem powerful and well-equipped for all sorts of high-end hardware. But exactly what you can put on an X299 motherboard depends a lot on the specific Skylake X or Kaby Lake X chip you plan to install. So, if you’re planning on building, you should carefully study the motherboard manual you’re considering, study the block diagrams and specs, to make sure all the parts you need will work with your CPU. Are you going to buy.

With the platform and chipset details aside, let’s take a closer look at the Core i9-7900X processor.

3.3GHz base clock is only a slight increase from last year’s Core i7-6950X, which has a 3GHz base clock. from 3.5 GHz in last year’s 10-core chip). And thanks to the aforementioned Turbo Boost Max 3.0 feature, two of these cores can run up to 4.5 GHz under certain conditions. Thus, the maximum theoretical speed of this chip exactly matches the Core i7-7700K. This is probably why, as we will see shortly, the chip Core i9matches a Core i7 processor in single-threaded benchmarks. This is an impressive feat, as Intel’s high-end, high-core-count chips have traditionally lagged behind more mainstream offerings in such tasks.

Before we dive into performance, let’s talk about thermals. On paper, the 140-watt thermal power (TDP) of the Core i9-7900K is the same as last year’s 10-core Core i7-6950X. But in our tests, the Core i9 tended to heat up even with slight overclocking. And this despite the fact that we used a liquid cooler with a large heatsink with three fans (more on this in a moment). And we weren’t the only reviewers to notice this issue.

We’ll look at this in more detail when we get to overclocking. But it’s worth noting here that if you’re planning on overclocking this chip, especially if you’re planning on doing time-consuming tasks like video encoding with increased core clock speeds, then you should also plan to invest in a very powerful liquid cooler. Intel does not ship these high-end chips with standard coolers. And even if you have a cooler that kept your previous high-end processor in the cooling zone, you should not automatically assume that it can do the same for this new processor.


For our test rig, we installed the Core i9-7900X on the Asus Prime X299-Deluxe motherboard we mentioned earlier, along with 32GB of Corsair memory running in a quad-channel configuration. Nvidia GeForce GTX 1080 Founders Edition video card handled the display output for our CPU-specific tests, and the Kingston HyperX Savage was the SATA boot drive. We could have used a faster PCI Express/NVMe drive, but since we tested previous Intel and AMD chips using SATA SSDs, we didn’t want to drop the speed demon and give Core i9-7900X unfair advantage. Such SATA SSDs are still highly respected.

We put all of these components in a Deepcool GamerStorm Genome ROG Certified(opens in a new window) case, which includes a standalone liquid cooler with a large three-fan heatsink. The thermal paste was Arctic Silver.

The previous generation Core i7-6950X Extreme Edition and the octa-core Core i7-6900K will be the main competitors of the Core i9, along with the AMD Ryzen 7 1800X. The latter is the highest-end Ryzen chip and AMD’s highest performing processor until this summer the promised Threadripper chips will not appear.

We also added an Intel Core i7-7700K to see how well this Core i9 paired with Intel’s top mainstream chip, and included a mid-range AMD Ryzen 5 1600X ($628.90 at Amazon) (opening in a new window) and Intel Core. i5-6600K chips for some perspective. Neither of the last two chips come close to the Core i9, but they will show how much pep you can get by spending a third or less of $999 for your current processor.

Cinebench R15

First in our test mode: Maxon Cinebench R15 CPU-intensive benchmark that is fully multi-threaded to use all available processor cores and threads, using the CPU rather than the GPU to render a complex image. The result is a proprietary score indicating PC suitability for CPU-intensive workloads. Along with the usual benchmark that uses all available cores, we’ve added single-core results here to see how AMD’s new chip handles low-threaded workloads.

Well that’s an impressive first for a Core i9 chip. The previous generation Core i7-6950X is up over 20 percent. Yes, and compared to the top-end Ryzen 7 1800X, the Core i9 chip performed 33 percent better.

iTunes 10.6 conversion test

We then switched to our venerable iTunes conversion test using version 10. 6 of iTunes. This test uses only one CPU core, like many legacy programs.

Music encoding certainly doesn’t push modern CPUs to their limits, and certainly not like these. Again, the Core i9 chip is here even with the Core i7-7700K. are inferior to their more mass-produced counterparts when it comes to tasks with a small number of threads.

Handbrake 0.9.9

Our traditional Handbrake test (performed in version 0.9.8) these days takes less than a minute with these high performance chips. (It includes rendering a 5-minute video of Pixar’s Dug’s Special Mission in an iPhone-friendly format.) So, we switched to a much more onerous (and time-consuming) video processing test that uses a nice, large chunk of 4K video.

In this test, we switched to the newer version of Handbrake 0.9.9 and instructed the processors to convert a 12 minute and 14 second 4K .MOV (4K Short Film Tears of Steel) file into a 1080p MPEG file. 4 videos…

The Core i9-7900X continues to impress, beating last year’s 10-core chip as well as the Ryzen 7 1800X by a full minute. take a look at the quad-threaded Core i5-6600K. It took almost three times as long to complete the same task as the Core i9 chip.This is the advantage a 20-thread processor gives you over a conventional chip that only runs four cores and doesn’t double the threads.

POV-Ray 3.7

Then, using the All CPUs option, we ran the POV-Ray test, which uses all available cores to render a complex photorealistic image using ray tracing. After that, to again understand how the Core i9 copes with single core performance, we ran the same test with the «Single CPU» setting.

We saw here more or less a reflection of what we saw in Cinebench. The Core i9 processor even outperformed the Core i7-7700K in the One CPU test and was about 20 percent ahead of last year’s 10-core chip in the All CPU test. while the Ryzen 7 1800X was a reasonable contender in this test with the Core i7-6950X, the AMD chip falls short of the Intel Core i9.

Blender 2.77a

Blender is an open source 3D content creation program that can be used to design and create visual effects, animations and 3D models for use in video games or 3D printing. We open a standard test file (this is a flying squirrel) and measure how long it takes the test processor to complete the rendering.

While all the results here were fairly close (with the exception of the Core i5 chip), the Core i9-7900X again outperformed any other. It also passed the 24-second ceiling that several recent high-end chips seemed to be stuck on. Intel.

7-Zip Benchmark 16.04

Finally, we fired up the popular 7-Zip file compression software and ran its built-in compress/decompress test, which is another useful test of a processor’s multi-core capabilities.

In this test, the Core i9-7900X performed about 11 percent better than its 10-core predecessor and a whopping 45 percent ahead of the AMD Ryzen 7 1800X. dollars, we’ll have to wait for Threadripper to see if AMD can stay competitive with Intel at a high level with its latest chips.


Overclocking was… an interesting experience with the Core i9-7900X.

On the one hand, we never had a system crash when turning on the processor. And technically we were able to get stable performance at 4.6 GHz with all cores. But with these settings, the Intel Extreme Tuning Utility (XTU) software told us that the chip often froze. And this despite the fact that the processor was connected to a standalone Deepcool cooler with a large 360mm radiator with three fans, which is part of the Genome ROG certified case (opens in a new window) (we are working on reviewing it) . ). We also often saw temperature spikes above 100 degrees Celsius at these settings, so we had to lower the clock speed to 4.3 GHz to keep the processor from getting too hot and slowing down.

Other reviewers seem to have had similar high temperature issues with other standalone coolers and custom cooling loops. In particular, Tom’s Hardware had to resort to an exotic compressor cooler(Opens in a new window) to keep the Core i9- 7900X when overclocked. So while the Core i9-7900X seems like a technically capable overclocker, you probably shouldn’t expect it to overclock much above stock settings unless you have a very powerful cooler. And even then, if you have nothing beats the cooling capabilities of most current self-contained liquid rigs, you’ll probably have to live with a chip running at high temperatures under continuous load.

Gaming performance

We usually don’t run graphics tests when testing processors without integrated graphics. This is mainly because graphics performance is usually much more dependent on what graphics card you have than what processor you are using. , especially when you’re talking about a chip as powerful as the Core i9-7900X.

But after testing AMD Ryzen chips, we noticed that they have problems with recent mainstream Intel Core i5 and Core i7 processors at 1080p in games. Many other reviewers do too. Considering this, as well as the fact that the Core i9The -7900X has a high core count similar to the Ryzen 7 chips, we wanted to see if the Core X line had similar issues. So we used the same Nvidia GeForce GTX 1080 Founders Edition card we tested with the Ryzen chips to run a couple of benchmarks. which we also use to test video cards.

For comparison, we did the same with our Intel Broadwell-E testbed with a Core i7-6950X processor. Both systems were tested using a Serial ATA-based boot SSD. MHz, at the same frequency we used when testing Ryzen chips using the XMP profile built into the motherboard. This is important because Ryzen chips tend to perform better at 1080p with faster RAM. And after some initial testing RAM at lower frequencies (2166 MHz) we can say that the same is true for the Core i9-7900X. When we increased the speed of the RAM, the frame rate also increased slightly.

First, we ran Late 2015 Rise of the Tomb Raider in DirectX 11 mode with the Very High preset and ran the built-in test. Our Ryzen 7 1800X based rig averaged 108 frames per second (fps), while the Core i9 chip with the same Nvidia card installed averaged 97 fps in the same test. But the Core i7-6950X averaged 127 fps with the same GTX 1080 card. 30fps is never good, especially when you consider how expensive high-end graphics cards are these days. But Intel Core i9 chipsand AMD, at least, were able to maintain fairly high frame rates.

As with the Ryzen chips, when we moved to 4K resolution (3840×2160), the performance leveled off, with the Broadwell-E, Ryzen 7 and Core i9 chips showing frame rates of around 48fps.

We then switched to playing Far Cry Primal at the High preset. At 1080p, the Core i9 (Core X) averaged 91 fps in this test, compared to the Ryzen 7 1800X’s lower 83 fps. But again, Core i9The -6950X delivered a noticeably better result of 108fps on the same test. And the Core i7-7700K on our Kaby Lake Z270 test bench delivered a much higher 130fps on the same test with the same Nvidia graphics card. However, when moving to At 4K resolution in Far Cry Primal, performance levels out again as different chips and platforms deliver 48 or 49 fps when running the same Nvidia graphics card.

What does this tell us? At least for these two Intel Core i9 tests-7900X seems to have the same performance issues as AMD Ryzen chips when paired with a high end card running at 1080p. So for those using high end graphics cards to play games with very high refresh rates (say above 100 Hz) at 1080p, Intel Core i7-7700K based builds are the best option.

But let’s not forget: even if you’re gaming on a 1080p screen, the nearly three-figure performance we’ve seen when testing with the Core i9-7900X, still very smooth. In the real world where most of us are still gaming (in the 60fps range), what the Core i9 provides, as we’ve said with AMD Ryzen chips, is more than enough for serious games.


We have been considering such chips from Intel for many years. And the almost standard conclusion for expensive chips with a large number of cores like these was something like this: this is overkill for almost everyone, and ordinary users (and gamers) should choose more cheap but more efficient. the main speed option (for example, Core i7-7700K). But if you’re a media pro and want all the cores and threads you can get, or you just want the best processor you can buy and don’t care about price, the first Core i9is an impressive choice. if that’s what you need.

But this time, a few changes have confused the reflective pool as we peer into it to see who the Core i9-7900K is best for. First, the chip effectively eliminates the mismatch problem between it and chips like the Core i7- 7700K, for single-core work. Both of them handle such tasks almost equally, which is very good. But, as we saw in our testing, at least some games work better on the Core i7-7700K and Core i7-6950X of the previous generation at 1080p. This is definitely bad — at least for gamers who are looking for the highest frame rate in mainstream resolutions.

The addition of additional PCI Express lanes, both on the chip itself and on the X299 chipset, makes Core X much more attractive to those who use a lot of bandwidth-demanding hardware in their builds. But Nvidia is now limiting its popular current generation Pascal graphics cards with just two cards in SLI. So unless you’re perhaps waiting for AMD Vega cards and planning on a four-way AMD CrossFireX setup using them, as well as a few high-speed SSDs, the number of available lanes is probably overkill as well . We have to assume that the number of people who will spend thousands to set up a VROC RAID with a lot of SSDs is also quite small. Our experience is that even one very fast PCI Express SSD does not feel noticeably faster in everyday use. than a solid state drive with an interface SATA catfish, and generally game load levels don’t speed up much. At this point, there’s no real, practical reason for almost everyone to go out of their way to build an insanely fast SSD boot drive array — at least other than the wow factor.

Then there’s the AMD Ryzen 7 chips. None of them come close to a Core i9 processor in our tests. But the eight-core Ryzen 7 1800X still keeps the Core i9 in the spotlight in many tasks, even though it costs less than $1,000, making it quite valuable if you also factor in the fact that AMD boards tend to cost less than X299 boards.

And for professionals and wealthy benchmark enthusiasts, there will soon be more powerful options in this category (and on the same X29 platform9) with as many as 18 cores. Of course, these more expensive Core i9 chips will cost more. (You saw pricing earlier in this review.) But as the continued existence of the Intel Core Extreme Edition platforms, and now the Core X platforms, has shown, cost doesn’t really matter to people who crave (or demand) extreme levels of processing power. We have there is a feeling that many of these buyers will be waiting for the Core i9-7980 Extreme Edition with its 36 threads until October. This chip should look almost modest by comparison.

So while the Core i9-7900X is better than its predecessor in almost every way, at $700 less, it’s a mid-range chip on a high-end platform, if you can imagine that. It’s still a powerful piece silicon that will serve you well if you’re a media creator or gamer who streams your frag sessions to the internet and also saves them in 4K on the fly for future use. Just make sure you set aside the extra cash for a powerful cooler, especially if you’re planning acceleration.

And if instead you opt for one of the lower-end Core X chips and plan to add a lot of other high-end components to your new build, be sure to spend a lot of time reading your future motherboard manual.