XFX GeForce 7800 GTX Graphics Card Review
Verdict
Key Specifications
- Review Price: £423.00
Big graphics hardware releases can often fall foul of two stumbling blocks – either the card doesn’t live up to the pre-release hype, or the hardware is super fast and exceeds expectations, but there’s no stock available for anyone to buy. Thankfully nVidia made sure that the GeForce 7800 GTX avoided both these pitfalls, and not only is it the fastest graphics card on the planet, it was also available in the retail channel from day one.
So, less than two weeks after the initial launch of the GeForce 7800 GTX, I’m writing this review of the XFX retail card. In fact I got the boards (XFX sent me two for SLi testing) just over a week after the launch, but I wanted to have a good play with them before writing up this review, so I made you wait a little while.
Unless you’ve been hiding in a cave for the past couple of weeks, you’re probably pretty familiar with the 7800 GTX specs, but in case you’re a bear and have just come out of hibernation I’ll give you a bit of background.
The GeForce 7800 GTX is nVidia’s new high-end graphics chipset, replacing the previous king of the hill, the GeForce 6800 Ultra. Now, the 6800 Ultra was a massive step forward when it was released just over a year ago, raising the transistor count to a heady 222 million, but the 7800 GTX smashes that landmark with an unbelievable 302 million transistors! The extra transistor count has helped nVidia raise the pixel pipelines from 16 to 24, while the vertex pipes have also increased from six to eight. nVidia has also opted to stick with the tried and tested 0.11 micron manufacturing process, rather than dropping down to a 90nm model, which could be the reason that yield is high straight off the bat.
The standard core speed of the 7800 GTX is 430MHz, which is an improvement over the standard core speed of the 6800 Ultra, which was 400MHz. However, many board partners clocked their retail 6800 Ultra cards faster than 400MHz, and it looks like the same is going to be true with the 7800 GTX.
XFX clearly thinks that the standard specs just aren’t fast enough and has clocked the core of its card at 450MHz. Likewise XFX has bumped up the memory speed slightly, with the 256MB of GDDR3 memory running at 625MHz (1.25GHz effective) instead of the standard 600MHz (1.2GHz effective). Coupled with the 256-bit memory interface, the XFX card should produce memory bandwidth of 40GB/sec compared to the 38.4GB/sec offered by the stock nVidia settings.
Although nVidia recommends a 500W power supply for running two GeForce 7800 GTX cards in SLi, I think that our green friends are definitely erring on the side of caution. Obviously the quality of the power supply comes into the equation, because the 460W Tagen power supply in the TrustedReviews graphics card test rig had no problems handling a pair of cards.
One criticism that was laid at the 6800 Ultra when it launched was the fact that it took up two slots inside your PC – a fact that was made worse when ATI launched its X800 cards in single slot form factor.
Thankfully nVidia has learned from its earlier experience and the 7800 GTX is a single slot card, albeit a very long one. The 7800 GTX also seems to run both quieter and cooler than the 6800 Ultra.
Now, don’t expect to see a plethora of different designs when you’re looking to buy a GeForce 7800 GTX card, since most board partners have just gone with the nVidia reference design, XFX included. It’s more likely that the differentiator between boards will be the clock speeds (as seen here) and the bundle that you get.
What you’re sure to get is dual DVI connectors, since this is part of the reference design. This is a great feature on any card and allows you to connect two LCD screens up digitally, for the best combination of desktop real estate and image quality. However, if your LCD only has an analogue connector, or if you want to use a CRT monitor, XFX has supplied two DVI to D-SUB converters in the box. If you’re wondering why anyone would want to connect a card like this to an old technology CRT monitor, keep reading and all will become clear.
Taking a look at monitors for a minute, the average PC user with a decent setup is probably using a 17in or 19in LCD screen with a resolution of 1,280 x 1,024. A true enthusiast user may have forked out the extra cash for a 1,600 x 1,200 20in or 21in LCD screen, while the totally loaded enthusiast may have treated himself to a 23in or 24in widescreen LCD with a resolution of 1,920 x 1,440. But the problem with all those screens, even the top end 24in widescreen display, is that they can’t produce a high enough resolution to do these cards justice.
When I tested these cards I had to drag out a large screen CRT monitor, since even when benchmarking a single card it didn’t really start to break a sweat until I cranked the resolution up to 1,920 x 1,440. But when it comes to running two cards in SLi, even a resolution of 2,048 x 1,536 didn’t seem to cause any problems.
Let’s take a look at Half-Life 2 first. Here you can see that the cards are CPU limited in the lower resolutions.
You can also see that there is a slight CPU overhead when running SLi, as the single card scores are actually higher at the lower resolution. Looking at the SLi scores you’ll see that the frame rate doesn’t drop below 100fps until you push the settings up to 1,920 x 1,440 with 4x FSAA enabled, and even then you’re still getting 95fps. Even running a single card you’re getting 66fps at the same resolution of 1,920 x 1,440 with 4x FSAA. But when you crank things up to 2,048 x 1,440 you start to see where the extra money you spent on an SLi solution is going – at this super-high resolution with 4x FSAA and 8x AF you’re still getting 68fps.
Of course I had to try out this setting, so I fired up Counter Strike: Source and started playing at 2,048 x 1,536 with 4x FSAA and 8x AF. The result was truly staggering, and I didn’t seem to suffer any major frame rate drops. Of course I had to tell everyone on the server what settings I was running, but no one believed me!
Loading up Far Cry showed a similar situation, but the most amazing observation is that the two cards in SLi were CPU limited all the way up to 2,048 x 1,536 if you run without FSAA or AF enabled – 1,024 x 768 scored 96.
17fps while 2,048 x 1,536 scored 94.82fps. Even when switching on FSAA and AF, the SLi setup didn’t drop below 90fps until I hit 1,920 x 1,440 with 4x FSAA. Far Cry is definitely still a pretty demanding engine, because running a single card showed the frame rate dropping to 62fps at 1,600 x 1,200 with 4x FSAA and 8x AF. If you want to push the resolution higher than this, you’re going to have to turn the image quality settings off, but you will be rewarded with a silky smooth frame rate.
Since I had a GeForce 7800 GTX SLi setup, I thought I might as well have a little play with the HDR lighting on Far Cry. Even pushing the resolution all the way up and setting the HDR at level seven produced a smooth enough frame rate for play. It has to be said that there are instances where the HDR effects are stunning, particularly the bits that nVidia likes to show off – looking up through a hole in the roof while underground for example. However, I do find the effects – in Far Cry at least – somewhat flawed.
The idea that I would get some kind of over saturated white out from the reflection of light on a wall seems a little unlikely to me. Also, although the idea of an image coming into focus as your eyes get used to the light is pretty cool, taking two steps backward shouldn’t then white it out again.
To be fair though, HDR in Far Cry was bolted on after the coding had been finished and the game released, so it’s probably not a perfect implementation. It does give you an idea of how good the lighting effects could be in future titles though. It also gives you something to do with cards like this if you don’t want to, or can’t push up to the silly resolutions that I’ve been testing with.
When nVidia released information to the Press before the launch of the 7800 GTX, it included some benchmark results that had been run in house. Of course I always take benchmark results provided by the manufacturer with a pinch of salt, but in this case I’ve seen faster results than those supplied by nVidia, despite using a very similar SLi test rig.
For instance, nVidia claims a 3DMark05 result of 8645 at 1,600 x 1,200 with 4x FSAA and 8x AF, while I managed 9121. Likewise, nVidia posted 85.6fps in Far Cry at the same settings, but I managed 91.6fps. Of course the extra performance is probably due to the slightly higher clock speeds sported by the XFX cards, but it’s always good when independent tests outstrip the manufacturer’s own numbers.
The XFX GeForce 7800 GTX is a fully ViVo compliant card, so you’ll be able to output and import video/audio signals. This is particularly important when you want to watch some HD video content on your large screen TV. The card will output either an S-Video signal, or the far preferable Component Video. However, the best way of outputting HD content will be over DVI, to a suitably equipped large screen LCD TV, but at least you’ve got all the bases covered.
As usual, XFX has shipped the card in a large X shaped box, which does look pretty cool. In the box you’ll find the card itself, two DVI to D-SUB converters, two S-Video cables, a ViVo cable with S-Video in, S-Video out, and component video out.
There’s also a twin Molex to six-pin PCI Express power converter, a driver disc, manual and a free T-Shirt.
Finally there’s a games bundle thrown in, and although X2: The Threat and Moto GP 2 are unlikely to get your pulse racing. Far Cry still looks as sweet as it did on the day it launched over a year ago.
So, how much are you going to have to pay for all this power? Well, as always, nothing this good ever comes cheap, and you’re going to have to dig pretty deep to buy one of these cards, but if you have SLi aspirations you’re going to have to be seriously flush. A single XFX GeForce 7800 GTX will set you back £422.87, so if you want SLi you’ll be looking at over £800 for graphics cards alone.
But despite the high price, I can’t help but love these cards. What I have in front of me is the current pinnacle of graphics technology – these cards will, quite simply, laugh at even the most demanding of 3D games. I guess I better start saving my pennies.
Verdict
This is the fastest graphics card ever to grace the TrustedReviews lab. The GeForce 7800 GTX is a totally awesome chipset, and the slightly overclocked XFX retail board pushed the envelope even further. If you’ve got a lot of money, buy one of these cards. If you’ve got even more money buy two – you won’t regret it.
Score in detail
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Value 8
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Features 10
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Performance 10
NVIDIA’s GeForce 7800 GT graphics cards
IF YOU’VE PURCHASED a GeForce 7800 GTX in the six weeks or so since its introduction, you may want to avert your eyes. If you purchased a Radeon X850 XT in recent months, just close your browser window now. And if you’re a corporate executive at a certain Canadian fabless semiconductor firm, you may want to bury your head. NVIDIA is now unleashing a card based on an ever so slightly cut down version of the G70 graphics processor at a substantial discount off the price of the GeForce 7800 GTX.
An army of cooling fans has been whirring nonstop here in Damage Labs for the past week or so to bring you an extensive set of benchmarks of the GeForce 7800 GT. The short version? The 7800 GT offers near-GTX performance for at least a hundred bucks less than NVIDIA’s top-end card, and it pretty much creams anything else in its price range. Keep reading for the full story.
What makes a GT
For those of you familiar with the GeForce 7800 GTX, getting a handle on the GT will be easy. If you’re unfamiliar with the 7800 GTX, well, then you need to go read our mind-enhancing review of NVIDIA’s seventh-gen GPU. The GeForce 7800 GT is based on the same G70 graphics processor that powers the GTX, but NVIDIA has disabled a few of the chip’s functional units for this less expensive card. I have done violence to a block diagram of a G70 GPU in order to illustrate what’s been disabled. Have a look:
Up top there, you can see that one of the G70’s eight vertex shader units, responsible for geometry processing, is crossed out with a big, red “X.
” This vertex unit is not functional in the 7800 GT, so the other seven will have to do. Across the middle, one of the six pixel-pipeline “quads” is crossed out, leaving the GeForce 7800 GT with a total of 20 pixel shader units. Without the services of these deactivated vertex and pixel shader units, the 7800 GT will perform a little bit slower than the 7800 GTX.
NVIDIA has also lowered the recommended clock speeds for the 7800 GT. A bone-stock GeForce 7800 GTX runs its GPU at 430MHz and its GDDR3 memory at 600MHz, while stock frequencies on the GT are 400MHz for the GPU and 500MHz for memory. Beyond that, little else has changed. The 7800 GT still has sixteen ROPs capable of writing one pixel per clock to memory, and it still has a 256-bit memory interface.
The cards
None of the GT’s spec changes should hamper its performance too much. The thing has more and better pixel pipes than a GeForce 6800 Ultra, for goshsakes. Still, NVIDIA’s board partners are already starting to push past the recommended specs, as they’ve done with the 7800 GTX.
Two of the three brands represented in our recent 7800 GTX roundup sell “overclocked in the box” cards, and some of the same suspects are tuning up the GT. BFG Tech’s GeForce 7800 GT OC, for instance, will sell with a 425MHz GPU and 525MHz memory. Meanwhile, the XFX cards we received for review are clocked at 450MHz with 525MHz memory.
XFX’s GeForce 7800 GT
In terms of basic layout and cooler design, I’d expect at least the first wave of 7800 GT cards to be entirely similar to the XFX card pictured above. At first glance, this looks very much like a 7800 GTXsame PCI Express connector, same dual DVI ports, same video in/out connector, same six-pin auxiliary power input. However, the 7800 GT board is actually about a half-inch shorter than a 7800 GTX, and the cooler is downsized, as well. That doesn’t mean, of course, that the 7800 GT is a smallish card; it’s still about an inch longer than a Radeon X850 XT Platinum Edition. It is smaller than a GTX, though.
Board makers aren’t just overclocking NVIDIA’s GeForce 7-series cards; they’re also underclocking prices.
NVIDIA’s initial estimated price on the 7800 GTX was $599, but cards are already selling for as low as $499 at online vendors. That’s no bargain, but it ain’t $599, either. In the same vein, I’d expect board makers to undercut NVIDIA’s suggested $449 list price somewhat on the 7800 GT. In fact, XFX says it will have its “overclocked in the box” 7800 GT selling at multiple online vendors, today, at $399.
Test notes
This was kind of a tough call, but because XFX shipped its 7800 GT to usa real retail product as of todaywith a 450MHz GPU clock and 525MHz memory clock, I decided to test the 7800 GT at that speed. Boards running at NVIDIA’s stock reference frequencies will be slightly slower than the XFX card we’re testing, but our results should be directly representative of a 7800 GT card you can buy right now. Had we received these cards and their drivers sooner than this past Friday, I would have been able to test the 7800 GT at stock reference speeds, as well.
Unfortunately, we just received them too late.
This decision will no doubt incite controversy because I did not include scores from an “overclocked in the box” GeForce 7800 GTX. If anyone has a coronary as a result, my apologies. You can see how an overclocked 7800 GTX performs in our multi-card roundup. The scores are more or less directly comparable to the ones in the following pages, save for the Splinter Cell: Chaos Theory numbers and a minor driver revision difference.
Speaking of which, you will notice in the test config tables below that we used NVIDIA’s 77.77 drivers for the GeForce 7800 GT and GTX cards, in both single-card and SLI setups. This represents a total refresh of the GTX test results from our GeForce 7800 GTX review and other recent graphics articles. However, the results for the GeForce 6800 Ultra were obtained using NVIDIA’s older 77.62 drivers. Between some serious time constraints and the fact that performance barely changed at all on the 7800 GTX when moving from 77.
62 to 77.77, I elected not to retest the GeForce 6800 Ultra with the 77.77 drivers. If the driver revision difference of 0.015 offends your sensibilities, just pretend the 6800 Ultra results aren’t there.
Similarly, I’ve included results from the Radeon X850 XT Platinum Edition using older Catalyst 5.6 drivers. Make of them what you will.
Also, note that I’ve included scores for a Radeon X800 XL 512MB card from Abit. Radeon X800 XL cards from other vendors are currently selling for between $359 and $400, or just below the likely price range of the 7800 GT. That makes the X800 XL competition, though not 100% direct competition. The X850 XT Platinum Edition might be the most direct competition for the 7800 GT in terms of price. I decided to include the X800 XL in part because I wanted to see how it performs at very high resolutions like 2048×1536. Perhaps the 512MB of video memory will be a help.
That said, remember that resolutions above three megapixels are something of a special case where the GeForce 7800s have architectural advantages over older GPUs.
Our testing methods
As ever, we did our best to deliver clean benchmark numbers. Tests were run at least three times, and the results were averaged.
Our test system was configured like so:
| Processor | Athlon 64 4000+ 2.4GHz | |||||||
| System bus | 1GHz HyperTransport | |||||||
| Motherboard | Asus A8N-SLI Deluxe | |||||||
| BIOS revision | 1011 | |||||||
| North bridge | nForce4 SLI | |||||||
| South bridge | ||||||||
| Chipset drivers | SMBus driver 4. 45IDE driver 5.18 |
|||||||
| Memory size | 1GB (2 DIMMs) | |||||||
| Memory type | OCZ EL PC3200 DDR SDRAM at 400MHz | |||||||
| CAS latency (CL) | 2 | |||||||
| RAS to CAS delay (tRCD) | 2 | |||||||
| RAS precharge (tRP) | 2 | |||||||
| Cycle time (tRAS) | 5 | |||||||
| Hard drive | Maxtor DiamondMax 10 250GB SATA 150 | |||||||
| Audio | Integrated nForce4/ALC850 with NVIDIA 4.  60 drivers |
|||||||
| Graphics | GeForce 6800 Ultra 256MB PCI-E with ForceWare 77.62 drivers | Dual GeForce 6800 Ultra 256MB PCI-E with ForceWare 77.62 drivers | XFX GeForce 7800 GT 256MB with ForceWare 77.77 drivers | Dual XFX GeForce 7800 GT 256MB with ForceWare 77.77 drivers | MSI GeForce 7800 GTX 256MB PCI-E with ForceWare 77.77 drivers | Dual MSI GeForce 7800 GTX 256MB PCI-E with ForceWare 77.77 drivers | Abit Fatal1ty X800XL 512MB PCI-E with Catalyst 5.7 drivers | Radeon X850 XT Platinum Edition PCI-E with Catalyst 5.6 drivers |
| OS | Windows XP Professional (32-bit) | |||||||
| OS updates | Service Pack 2 | |||||||
Thanks to OCZ for providing us with memory for our testing.
If you’re looking to tweak out your system to the max and maybe overclock it a little, OCZ’s RAM is definitely worth considering.
Unless otherwise specified, the image quality settings for both ATI and NVIDIA graphics cards were left at the control panel defaults.
The test systems’ Windows desktops were set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.
We used the following versions of our test applications:
- trdemo2 demos
- Far Cry 1.3 with tr1-volcano and tr3-pier demos
- Splinter Cell: Chaos Theory 1.04 with trpenthouse demo
- The Chronicles of Riddick: Escape from Butcher Bay 1.1 with trdemo4
- FutureMark 3DMark05 Build 120
All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.
Pixel filling power
We can handicap the 7800 GT’s performance prospects to some extent by looking at some key theoretical performance numbers.
The raw ability to paint pixels onscreen at a certain rate isn’t exactly destiny for today’s graphics cards, but it’s still an important metric. Here’s how the 7800 GT stacks up.
| Core clock (MHz) |
Pixels/ clock |
Peak fill rate (Mpixels/s) |
Textures/ clock |
Peak fill rate (Mtexels/s) |
Memory clock (MHz) |
Memory bus width (bits) |
Peak memory bandwidth (GB/s) |
|
| GeForce 6800 | 325 | 12 | 3900 | 12 | 3900 | 700 | 256 | 22. 4 |
| GeForce 6600 GT | 500 | 4 | 2000 | 8 | 4000 | 1000 | 128 | 16.0 |
| Radeon X800 | 400 | 12 | 4800 | 12 | 4800 | 700 | 256 | 22. 4 |
| GeForce 6800 GT | 350 | 16 | 5600 | 16 | 5600 | 1000 | 256 | 32.0 |
| Radeon X800 XL | 400 | 16 | 6400 | 16 | 6400 | 980 | 256 | 31. 4 |
| GeForce 6800 Ultra | 425 | 16 | 6800 | 16 | 6800 | 1100 | 256 | 35.2 |
| GeForce 7800 GT | 400 | 16 | 6400 | 20 | 8000 | 1000 | 256 | 32. 0 |
| Radeon X850 XT | 520 | 16 | 8320 | 16 | 8320 | 1120 | 256 | 35.8 |
| Radeon X850 XT Platinum Edition | 540 | 16 | 8640 | 16 | 8640 | 1180 | 256 | 37. 8 |
| XFX GeForce 7800 GT | 450 | 16 | 7200 | 20 | 9000 | 1050 | 256 | 33.6 |
| GeForce 7800 GTX | 430 | 16 | 6880 | 24 | 10320 | 1200 | 256 | 38. 4 |
A stock 7800 GT has a higher theoretical peak multitextured fill rate (the more important kind, usually) than a GeForce 6800 Ultra, but a little less than a Radeon X850 XT. The XFX card we’re testing today, though, can push more multitextured pixels than even a Radeon X850 XT Platinum Edition. In terms of memory bandwidth, the 7800 GT is closer to the Radeon X800 XL. This mix of pixel fill rate and memory bandwidth puts the 7800 GT in an interesting place.
Let’s see how the theory translates into performance with some basic synthetic fill rate benchmarks.
These results track pretty well with the theoretical capabilities of the cards. As one would expect, the XFX 7800 GT comes out just ahead of the Radeon X850 XT Platinum Edition in multitextured fill rate. The 7800 GT doesn’t trail the 7800 GTX by too terribly much, either. Let’s see how these numbers translate into performance in games.
Doom 3
We’ve conducted our testing almost exclusively with 4X antialiasing and a high degree of anisotropic filtering.
We generally used in-game controls when possible in order to invoke AA and aniso. In the case of Doom 3, we used the game’s “High Quality” mode in combination with 4X AA.
Our Delta Labs demo is typical of most of this game: running around in the Mars base, shooting baddies. The new and imaginatively named “trdemo2” takes place in the game’s Hell level, where the environment is a little more varied and shader effects seem to be more abundant.
Notice how that orange line snuggles up just underneath the green one through all four resolutions in both graphs. The 7800 GT just barely trails its big brother, the 7800 GTX, in Doom 3. With SLI, the story is the same, but at much higher speeds. The ATI cards just can’t keep up.
Far Cry
Next up is Far Cry, which takes advantage of Shader Model 3.0 to improve performance. The game also has a path for ATI’s Shader Model 2.0b. Our first demo takes place in the jungle with lots of dense vegetation and even denser mercenaries.
All of the quality settings in the game’s setup menu were cranked to the max.
Our next demo takes place on the Volcano level, where there’s a whole lot of heat shimmer going on. Pixel shading power should be at a premium here.
Far Cry is much more of a contest, as the performance of the Radeon X850 XT Platinum Edition tracks very closely with the 7800 GT’s at the three lower resolutions. Also, the Radeon X800 XL 512MB seems to benefit from having more memory onboard here. Note that it surpasses the GeForce 6800 Ultra and the Radeon X850 XT PE at 2048×1536.
The Chronicles of Riddick: Escape from Butcher Bay
This game has a Shader Model 3.0-type mode, but to keep things even for comparison to the Radeon, I ran all cards with the SM2.0 path.
Like Doom 3, Riddick is an OpenGL game. That may explain in part why the ATI cards struggle so much here; NVIDIA’s OpenGL drivers may be better. Whatever the case, the 7800 GT puts in a heckuva showing, again trailing the GTX by only a hair.
Splinter Cell: Chaos Theory
We’re using the brand-new 1.04 version of Splinter Cell: Chaos Theory for testing, and that gives us some useful tools for comparison. This new revision of the game includes support for Shader Model 2.0, the DirectX feature set used by Radeon cards. The game also includes a Shader Model 3.0 code path that works optimally with GeForce 6 and 7-series GPUs. Because SM2.0 and SM3.0 can produce essentially the same output, we’ve tested the ATI cards with SM2.0 and the NVIDIA cards with SM3.0. (The game won’t let NVIDIA cards run in SM2.0 mode, although they are capable of doing so.)
In our first test, we enabled the game’s parallax mapping and soft shadowing effects. In the second, we’ve also turned on high-dynamic-range lighting and tone mapping, for some additional eye candy. Due to limitations in the game engine (and in NVIDIA’s hardware), we can’t use HDR lighting in combination with antialiasing, so the second test was run without edge AA.
The Radeon X850 XT PE is more than competitive with parallax mapping and soft shadows enabled, but the 7800 GT separates itself from the ATI card once HDR lighting comes into play. The ATI cards don’t have dedicated hardware with floating-point texture filtering and blending capabilities, so they have to rely on their pixel shaders to do the job. The G70’s native support for 16-bit floating point filtering and blending probably gives it an edge.
3DMark05
The 7800 GT’s performance in 3DMark’s three main game tests more or less confirms what we’ve seen elsewhere. The GT is faster than the Radeon X850 XT Platinum Edition, and it can nearly keep up with the 7800 GTX. SLI, of course, opens up a whole new realm of speed.
The G70’s revamped pixel shaders allow the 7800 GT to post some astounding numbers in 3DMark’s pixel shader test, well above the fastest card that ATI has to offer and just below the 7800 GTX once again. As for vertex shaders, it seems the 7800 GT’s one disabled vertex unit isn’t much of a handicap.
The GT’s scores track very closely with the GTX’s, although the Radeon X850 XT PE is the fastest single card in the vertex shader benchmarks.
Power consumption
We measured total system power consumption at the wall socket using a watt meter. The monitor was plugged into a separate outlet, so its power draw was not part of our measurement. The idle measurements were taken at the Windows desktop, and cards were tested under load running a Doom 3 timedemo of our “trdemo2” in High Quality mode at 1280×1024 with 4X antialiasing.
The system based on the 7800 GT draws less power, both under load and when idle, than the systems based on cards it outscores in the benchmarks, including the GeForce 6800 Ultra and the Radeon X850 XE Platinum Edition. In fact, at idle, the 7800 GT system pulls fewer watts than anything in the group.
These results aren’t surprising given how quiet the 7800 GT’s cooler is. At idle, the thing is simply inaudible over the sound of the CPU and chipset coolers in our test system.
Under load, the cooler is audible on an open test bench, but probably wouldn’t be when placed inside of a computer case.
Overclocking
I was able to overclock a single 7800 GT card to 491MHz core/565MHz memory simply by using the built-in speed detection button in the NVIDIA driversthat’s 41MHz over the XFX’s stock GPU speed and 91MHz over the NVIDIA-recommended speed. Things were a little different with two 7800 GTs in SLI, where NVIDIA’s utility picked a 475MHz max core clock speed with 540MHz memory. In both cases, my attempts to push for higher core speeds manually were unsuccessful. Nevertheless, the cards were stable at the speeds that the driver chose for them, with no visible artifacts and no crashes.
The 7800 GTX’s slight edge evaporates when the 7800 GT is overclocked to its limits. Of course, there’s some overclocking headroom built into the GTX, as well, so that’s no surprise. Still, the 7800 GT’s overclocked performance is impressive.
Conclusions
So, like I said at the outset, the card is fast, and it’s less expensive than the GeForce 7800 GTX.
The performance differences between the two were narrowed a little bit in our testing because we used an “overclocked in the box” GeForce 7800 GT and a stock-clocked GTX. Even so, I’d have a hard time finding the justification for spending an extra hundred-plus dollars on a 7800 GTX now that the 7800 GT has arrived. None of these cards are cheap, but the 7800 GT is easily a better value than its pricier sibling. Either card will get you the full feature set of NVIDIA’s G70 GPU, and the performance delta between them isn’t huge.
If it’s absolute performance you crave, then grab yourself a pair of 7800 GTs and run them together in SLI. A 7800 GT SLI rig ought to satisfy even the most insanely graphics-crazed person. Personally, though, I wouldn’t spring for a full SLI setup right now, because few current games really need that kind of power. I’d stick to a one-card setup, but I’d make darn sure my motherboard would allow me to add a second card down the road.
As for the competition from ATI, well, realistically, it hasn’t been introduced yet.