850 EVO vs 840 EVO, which is the better Samsung SSD? -One Computer Guy
The difference between Samsung 840 EVO and 850 EVO is mainly related to the read and write speed, their capacities, and the write endurance of the drive.
Both are internal solid-state drives two and a half inches wide and designed to go inside the case of the computer as the main drive or backup drive. Find below a comparison of the two drives and the advantages and disadvantages of each.
Contents
- 840 EVO vs 850 EVO Specifications
- 1. Samsung 840 EVO
- 2. Samsung 850 EVO
- Samsung 840 EVO and 850 EVO Benchmark data
- 1. Samsung 840 EVO Performance
- – Samsung 840 EVO Benchmark
- 2. Samsung 850 EVO Performance
- – Samsung 850 EVO Benchmark
- – Write Endurance
- Conclusion
840 EVO vs 850 EVO Specifications
|
|
Samsung 850 EVO | Samsung 840 EVO |
| Capacity | 120 GB, 250 GB, 500 GB, 1 TB, 4TB | 120 GB, 250 GB, 500 GB, 750 GB, 1 TB |
| Connection | SATA | USB, SATA, mSATA |
| Feature | Solid State Drive | Solid State Drive |
| Form Factor | 2. |
2.5 Inch Drive |
| Type | Internal | Internal |
1. Samsung 840 EVO
Connections: USB, SATA, mSATA
Features: 2.5 Inch Internal drive
Design aesthetics: Silver drive
Considerations:
- Single layer chips
- Older technology
- Smaller chips
- Shorter lifespan
- 3 Year Warranty
The Samsung 840 EVO has three available connections depending on the type of motherboard you have, but if you have the ability to use SATA over USB, you are going to want to do so to take advantage of the speed.
Both SATA and mSATA meet the requirements of 6 Gb/s but USB only reaches 5 Gb/s. If you only have the space to use mSATA, this drive can accommodate that requirement.
As the internals of a computer are increasingly put on display with windowed cases and full-color spectrum components, the design aesthetic of the Samsung 840 EVO is something to consider as well.
The 2.5 inch drive is housed in a silver casing which will reflect light from any RGB components and contribute to the colored interior of the computer.
The Samsung 840 EVO uses older, single-layer chip technology which means it takes longer for the drive to communicate with the computer you are using.
addition to having slower read and write speeds, the Samsung 840 EVO lifespan is shorter than the Samsung 850 EVO. The Samsung 840 EVO can only endure approximately 3000 write cycles as opposed to 6000 with the Samsung 850 EVO
If reliability and warranty is something you look for in your drive, then be aware that the Samsung 840 EVO only comes with a 3-year warranty when its competitor the Samsung 850 EVO comes with five.
2. Samsung 850 EVO
Connections: SATA
Features: 2.5 Inch Internal Drive
Design Aesthetics: Black drive
Considerations:
- Larger chips
- Stacked 32 layers deep
- Longer lifespan
- Faster memory access
- 5 Year Warranty
Unlike the Samsung 840 EVO, the Samsung 850 EVO only accommodates connection by SATA.
This eliminates the choice between running the drive over USB vs SATA, but also means that this drive cannot use the smaller, mSATA connection.
The design aesthetic of the Samsung 850 EVO is something to consider as well in the world of computer cases with windowed sides. The 2.5 inch drive is housed in a black casing, which will blend with the sleek and seamless look of high-end gaming set up with other black components.
The chips in the Samsung 850 EVO are stacked which reduces the physical distance between the silicon layers and increases the speeds at which data can be accessed from the drive.
The Samsung 850 EVO also boasts a 5 year warranty covering the drive, giving the buyer extended peace of mind with regard to reliability, in contrast to the 3-year warranty available with the Samsung 840 EVO.
Samsung 840 EVO and 850 EVO Benchmark data
The main difference between 840 EVO and 850 EVO is, Samsung 840 EVO Faster read speed on larger drives while Samsung 850 EVO has faster read and write speed, both random and sequential.
1. Samsung 840 EVO Performance
| 120 GB | 250 GB | 500 GB | 750 GB | 1 TB | |
| Random Read (higher is better) | 91.7 MB/s | 94 MB/s | 90 MB/s | 95.3 MB/s | 96 MB/s |
| Random Write (higher is better) | 147.8 MB/s | 266.4 MB/s | 270.3 MB/s | 272.9 MB/s | 271.9 MB/s |
| Sequential Read (higher is better) | 429.8 MB/s | 426.8 MB/s | 409.8 MB/s | 405.7 MB/s | 428.7 MB/s |
| Sequential Write (higher is better) | 172.9 | 285.8 MB/s | 375 MB/s | 375.7 MB/s | 374 MB/s |
| Turbo Write Cache | 3 GB | 3 GB | 6 GB | 9 GB | 12 GB |
| Die Configuration | 8 x 128 GB | 16 x 128 GB | 32 x 128 GB | 48 x 128 GB | 64 x 128 GB |
– Samsung 840 EVO Benchmark
The four elements of SSD performance are generally considered to be the following: random read speed, random write speed, sequential read speed, and sequential write speed.
Random accesses are generally small, and sequential accesses are generally larger, but that does not necessarily mean random reads and writes are faster than their sequential counterparts.
Compared to the Samsung 850 EVO, the Samsung 840 EVO has the following advantages:
- Faster read speed on larger drives
Comparing the different sizes of the Samsung 840 EVO, they have the disadvantage of their 120 GB drive and their 1 TB drive of not performing as well as the 250 GB, the 500 GB, and the 750 GB drives. For the Samsung 840 EVO, the drive size with the best overall performance is the 750 GB drive.
The EVO 840 has a random read between 90 and 96 MB/s, and the 1 TB Samsung EVO 840 generally performs better in both the random and sequential read than the comparable 1 TB Samsung EVO 850. Despite the fact that the Samsung EVO 840 outperforms the Samsung EVO 850 at that size, the overall performance of the Samsung 840 EVO drops off when comparing the Samsung EVO 840 750 GB drive to the Samsung EVO 840 1 TB drive.
The EVO 840 features a second-level cache. On the 120 GB and 250 GB EVO 840 this is a 3 GB Turbowrite cache (TWC), a block of high-speed flash memory. On larger sizes another 3 GB is added to the TWC. Write speeds can drop by approximately 50% when this cache is used up, but under typical consumer read and write operations it won’t happen very often.
With eight parallel NAND channels and the ability to address four chips per channel, the EVO’s controller needs at least 32 dies for optimal performance. Therefore, only the 500GB and larger models deliver on the full potential of the drive. The 120 GB and 250 GB models predictably have lower write performance.
Because of this disadvantage in the die configuration, the 120 GB and the 250 GB sizes have the most to gain from the Turbowrite cache, though it does take up a larger portion of the drive space on the smaller drives compared to the large ones.
Looking at raw performance numbers, even with the Turbowrite cache, the EVO 840 still doesn’t reach the speeds of some of the fastest drives on the market.
It has a speed index reading of 439 MB/s which puts the EVO 840 within striking distance of the two speed leaders (Vector and 850 Pro). The Samsung EVO 840 is cheaper than the Samsung EVO 850, and it is one of the best values for the cost of an internal SSD.
2. Samsung 850 EVO Performance
| 120 GB | 250 GB | 500 GB | 1 TB | |
| Random Read (higher is better) | 101.6 MB/s | 103.9 MB/s | 104.5 MB/s | 89.6 MB/s |
| Random Write (higher is better) | 170.2 MB/s | 298.6 MB/s | 301.7 MB/s | 285.5 MB/s |
| Sequential Read (higher is better) | 447.7 MB/s | 421 MB/s | 421.5 MB/s | 419.5 MB/s |
| Sequential Write (higher is better) | 186.8 MB/s | 320 MB/s | 391. 3 MB/s |
379.1 MB/s |
– Samsung 850 EVO Benchmark
Compared to the Samsung 840 EVO, the Samsung 850 EVO has the following advantages:
- Generally faster read and write speed, both random and sequential
When considering the four elements of SSD performance: random read speed, random write speed, sequential read speed, and sequential write speed, the Samsung EVO 850 outperforms the Samsung EVO 840 in most categories at comparable sizes.
The Samsung 840 EVO only outperforms the Samsung 850 EVO at the 1 TB size. Across the board, the Samsung 850 EVO has faster random read speed, faster random write speed, faster sequential read speed and sequential write speed. The best performing size of the Samsung 850 EVO is the 500 GB drive.
Like the Samsung 840 EVO, the Samsung 850 EVO suffers a loss in performance at the 120 GB size and 1 TB size compared to the sizes in the middle.
The random read speed of the 1 TB drive is only 89.6 MB/s compared to 104.5 MB/s for the 500 GB, and the sequential write speed of the 120 GB drive is only 186.8 MB/s compared to 391.3 MB/s for the 500 GB size.
The Samsung 850 EVO is one of the fastest Samsung SSDs available on the market, consistently outperforming its competitor, the Samsung 840 EVO. Thanks to Samsung’s new 3D V-NAND the 850 also generally consumes less power and performs better than both the 840 Evo and 840 Pro. These drives effectively saturate SATA 3.0 making it difficult to distinguish between them during daily use.
– Write Endurance
A solid state drive’s lifespan is measured by the number of write cycles it can undergo. The Samsung 840 EVO write endurance is approximately 3000 cycles, and on the Samsung 850 EVO this is approximately 6000 cycles.
In contrast to conventional hard drives, the mechanics of solid state don’t degrade when only reading data.
This means a solid state drive only undergoes wear when writing data, not when reading it.
Samsung’s warranty includes a provision for the total amount of data written to the drive as well, which for the Samsung 850 EVO is 75 terabytes written to the drive for the 120 GB and 250 GB sizes, and 150 terabytes written for the 500 GB and 1 TB sizes.
Both drives will last several years, but the Samsung 850 EVO can withstand significantly more write cycles than the Samsung 840 EVO which adds value if you know you use your drive to do a lot of write operations over its lifetime.
Conclusion
If you know you only have use for a drive approximately 500 GB in size and read and write speed are particularly important to you, then it would be worth the extra money to get the 500 GB Samsung 850 EVO. It has the fastest read and write speeds of the Samsung 850 EVO line and is even faster than the 750 GB Samsung 840 EVO.
If you know you need a drive bigger than 500 GB and you are also looking to save a little money, the Samsung 840 EVO will be more than sufficient, particularly if you need 1 TB of storage, because this is where the Samsung 840 EVO has an advantage in speed over the Samsung 850 EVO.
Review: Samsung SSD 840 EVO (120GB) — Storage
And here we were, staring multiple SandForce drives in the face, thinking solid-state innovation had ground to a halt. How wrong we were. Boffins at some of the biggest names in the industry have proven that there’s plenty of room for improvement, with Intel introducing a new level of consistency across the SATA 6Gbps interface and Crucial showing us that high-capacity SSDs needn’t cost the earth.
Up next? Samsung, who’s here to tell us that affordable, low-capacity drives don’t have to offer second-rate performance when compared to larger drives in the same range.
It’s a familiar problem, and one what does need tackling. Take the recently launched Crucial M500 as an example — great drive, but the low-cost 120GB model takes a 68 per cent performance hit in terms of sequential write speed when compared to the range-topping 960GB drive.
It’s that massive gap that Samsung is attempting to narrow with the new 840 EVO. Designed as a successor to the popular 840 Series, the EVO drive slots in below the top-of-the-line 840 PRO and aims to offer an affordable upgrade path to those looking to take their first steps into solid-state territory. At launch, the EVO Series drive will be available in a choice of 120GB, 250GB, 500GB, 750GB and 1TB capacities, with prices ranging from £87 to £510.
Samsung SSD 840 EVO Series |
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|---|---|---|---|---|---|---|
| Model |
120GB |
250GB |
500GB |
750GB |
1TB |
|
| Controller |
Samsung 3-core MEX Controller |
|||||
| NAND |
19nm Samsung Toggle DDR 2. |
|||||
| Onboard DDR2 Cache |
256MB |
512MB |
512MB |
1GB |
1GB |
|
| Interface |
SATA 6Gb/s, compatible with SATA 3Gb/s and 1.5Gb/s |
|||||
| Sequential Read Speed |
up to 540 MB/s |
up to 540 MB/s |
up to 540 MB/s |
up to 540 MB/s |
up to 540 MB/s |
|
| Sequential Write Speed |
up to 410 MB/s |
up to 520 MB/s |
up to 520 MB/s |
up to 520 MB/s |
up to 520 MB/s |
|
| Random IOPs (4KB Reads, QD32) |
up to 94,000 IOPs |
up to 97,000 IOPs |
up to 98,000 IOPs |
up to 98,000 IOPs |
up to 98,000 IOPs |
|
| Random IOPs (4KB Writes, QD32) |
up to 35,000 IOPs |
up to 66,000 IOPs |
up to 90,000 IOPs |
up to 90,000 IOPs |
up to 90,000 IOPs |
|
| Dimensions (LxWxH) |
100 x 69. |
|||||
| Active Power Consumption |
0.1W Typical |
|||||
| Idle Power Consumption |
0.045W Typical |
|||||
| Life Expectancy |
1.5 million hours Mean Time Between Failures (MTBF) |
|||||
| Endurance |
72TB total bytes written (TBW), equal to 40GB per day for 5 years |
|||||
| Warranty |
3 Years |
|||||
| Retail Price | Basic |
£86.99 |
£148.99 |
£289.99 |
£415.99 |
£509.99 |
| w/ Laptop Kit |
N/A |
£156.99 |
£297.99 |
N/A |
N/A |
|
| w/ Desktop Kit |
£97. |
£160.99 |
N/A |
N/A |
N/A |
|
0 NAND Flash Memory (400Mbps)
85 x 6.8 (mm)
99The read and write speeds of the spacious 1TB drive are rated at 540MB/s and 520MB/s, respectively, but what’s interesting is that the cheap-and-cheerful 120GB model isn’t far behind — it claims to offer 540MB/s reads and 410MB/s writes, which is impressive for a low-capacity drive.
So how has Samsung managed to loosen the previously tight link between performance and capacity? As we know, today’s SSDs utilise multi-channel controllers and are able to offer optimal performance when numerous NAND memory chips are interfacing with the processor in parallel.
Taking a look inside the 120GB EVO SSD suggests that the problem should, if anything, be exaggerated. Samsung has just a pair of 19nm NAND memory chips (one either side of the mini-PCB) hooked up to a triple-core controller and a modest 256MB onboard DDR2 cache.
Creating all the components in-house is an obvious advantage — they should work in harmony when set to task by Samsung’s proprietary firmware — but two NAND chips, a multi-channel controller and a small DDR2 cache is hardly a recipe for blazing speed.
There has to be something else afoot, and there is; both in terms of hardware and software.
First and foremost, Samsung has increased the speed of the controller. The new chip, dubbed MEX, is based on the same triple-core ARM Cortex R4 architecture, but is now clocked at 400MHz; a full 100MHz faster than the previous MDX. A bump in core frequency is typically the way to increase performance, but the 840 EVO’s real party tricks are two new technologies dubbed TurboWrite and RAPID (Real-time Accelerated Processing of I/O Data) Mode.
record 1 petabyte The goal is to check how many rewrite cycles each of the six instances can withstand. The experiment continues to this day: after writing 1 petabyte, three drives remained alive.
Anvil’s Storage Utilities program was chosen for testing. In general, these models are not as interesting as the pathogenesis of deceased «patients». All of them, shortly before their death, began to work a little more slowly, but broke down for various reasons.
Intel 335 Series 240GB and Kingston HyperX 3K 240GB drives generated numerous imminent failure warnings, although at the very end they completely stopped responding to external stimuli.
But the Samsung 840 240GB, which uses the more fragile TLC NAND flash memory, died without warning, except for failures. He suffered during the life of the failure of individual memory cells and numerous fatal errors. It managed to record 900 TB, with 119 of the 295 uncorrectable errors between 800 and 900 TB, and almost all of the rest in the 300 TB region, that is, after running a data retention test without power for several days.
All three dead SSDs ended in a state where data could not be recovered from them. In particular, the Intel drive went into read-only mode, and after turning off and on the power activated something like a self-destruct procedure and completely failed (perhaps this was due to an attempt to write to a disk that was in read-only mode). It was still detected by the driver, but only as a 0GB SATA device.
Although six instances are clearly an insufficient statistical sample, all of them exceeded their stated lifetime by hundreds of terabytes. In particular, each managed to record more than 700 TB. This proves the very high reliability of modern consumer segment SSDs. All the more impressive are the performance of drives that continue to work even after a petabyte: these are the Corsair Neutron GTX 240GB, the Samsung 840 Pro 256GB and the second Kingston HyperX 3K 240GB (with data compression).
Due to built-in data compression, the Kingston HyperX 3K recorded only 716 TB of recorded data, even though a petabyte was sent to it. There are no failures yet: only two moved sectors.
Corsair Neutron GTX, according to the built-in Toolbox and SSD life left indicator, generally feels like new.
The Tech Report promises to kill the remaining three drives and tell how they died.
By the way, several years ago Google published statistics on HDD failure in its data centers.
It follows from it that the occurrence of failures is not related to the amount of information written to the disk, but it positively correlates with the number of starts-stops of the disk and negatively correlates with temperature: the colder, the more often failures occur.
New Samsung 840 Evo Read Speed Patch Coming This Month / Sudo Null IT News0038
For half a year, a defect in Samsung 840 Evo solid-state drives has been in place, which leads to a decrease in the speed of reading old data. Last year, users began to complain that the speed of reading information written to a disk more than 30 days ago drops several dozen times. By the end of September, technical publications drew attention to the problem, and later the manufacturer himself.
The Performance Restoration Tool was released in October to fix this problem. Then the South Korean giant said that the eight states of the three-bit cells were incorrectly calibrated. Months after the first fix, some 840 Evo owners have experienced the same degradation problem, although this time around it’s not as severe.
Samsung says that as early as April this year, a new firmware version with a periodic update function will be released.
Samsung 840 Evo are drives from 120 gigabytes to 1 «honest» terabyte, available in form factors for connecting via SATA and mSATA. Immediately after the appearance, thanks to the aggressive pricing policy and good performance, they were one of the best solid state for home use. After some time, users began to notice something strange: the data recorded several months ago could no longer be read at full speed.
This is how the problem appeared six months ago.
840 Evo uses TLC NAND memory, which stores 3 bits per cell, which requires correct calibration of eight voltage levels at once. As Samsung representatives stated, these levels changed over time, and the firmware was not ready for this, so the controller made many requests, trying to read the information. (Fortunately, flash memory does not wear out from reading.
) As a result, data retrieval rates from cells older than 30 days dropped to 15-20 megabytes per second. The manufacturer reacted quickly, and by the end of October, the Performance Restoration Tool utilities for Windows, OS X and Linux were released. The program updated the disk firmware and completely overwrote its contents.
It was then claimed that this patch completely fixed the problem, but this turned out not to be the case. Some users began to report repeated subsidence in reading speed. In comparison with the first case, the problems were not so strong — 400-450 MB / s dropped to about 150, but it became clear that the first attempt did not completely correct the situation. In February of this year, Samsung acknowledged the problem and promised to release an update «in March».
A later message said that the new utility would be released at the end of April. It will contain a tool to automatically periodically overwrite data to restore speed. Upon reaching a certain age, the data on the solid state will be overwritten.
Samsung claims that this operation will be carried out in the background and will not affect the overall performance of the system. Before the release of the first fix in October, some users solved the problem in exactly the same way — by completely overwriting the old data. This negatively affects the life of the drive, but if the new firmware does this once every few weeks or months and only for a small part of the drive, then the effect will be minimal.
Once released, the new firmware can be obtained from the Samsung Magician 4.6 tool. Only owners of the 840 Evo need to worry, no similar problems have been found in the 840 and 850 Evo. An overview of the unreleased version 4.6 is already available on the PC Perspective website. The new firmware will add an automatic overwrite process that will take place during idle time without any user intervention. But if you need to force the recovery process (the disk was disconnected for a long time or heavily loaded), you should manually start Magician and carry out the Advanced Performance Optimization operation.