Controller: Samsung 3-core MDX. Flash Memory: Samsung 21nm Toggle Mode MLC.

Controller: Samsung 3 Core MEX. Memory: Samsung 19nm Toggle Mode TLC.

Real World Speed
Performance profile from 33,919 user samples
7,628 User Benchmarks
Best Bench: 99% 36GB free
Worst Bench: 53% 31GB free
Poor: 53% Great: 99%
SPEED RANK: 209th / 850
26,291 User Benchmarks
Best Bench: 94% 35GB free
Worst Bench: 58% 32GB free
Poor: 58% Great: 94%
SPEED RANK: 202nd / 850
Effective Speed
Effective SSD Speed
78.3 % -1% 78.9 % +1%
Avg. Sequential Read Speed
486 MB/s +2% 478 MB/s -2%
Avg. Sequential Write Speed
306 MB/s -3% 315 MB/s +3%
4K Read
Avg. 4K Random Read Speed
28.9 MB/s -29% 37.4 MB/s Faster random read.
4K Write
Avg. 4K Random Write Speed
77.3 MB/s Much faster random write.
59.4 MB/s -30%
Avg. Sequential Mixed IO Speed
335 MB/s Slightly faster mixed IO speed.
308 MB/s -9%
4K Mixed
Avg. 4K Random Mixed IO Speed
20 MB/s +2% 19.6 MB/s -2%
Peak Sequential Read Speed
521 MB/s +4% 501 MB/s -4%
Peak Sequential Write Speed
440 MB/s Faster peak write speed.
352 MB/s -25%
4K Read
Peak 4K Random Read Speed
36.1 MB/s -26% 45.5 MB/s Faster peak random read.
4K Write
Peak 4K Random Write Speed
118 MB/s Much faster peak random write.
83.1 MB/s -42%
Peak Sequential Mixed IO Speed
477 MB/s Much faster peak mixed IO speed.
345 MB/s -38%
4K Mixed
Peak 4K Random Mixed IO Speed
25.4 MB/s +1% 25.1 MB/s -1%
Market Share
Based on 2,859,716 SSDs tested.
Market Share
Market Share (trailing 30 days)
0.6 % -212% 1.87 % Hugely higher market share.
Value For Money
37.4 % -14% 42.8 % Slightly better value.
User Rating
UBM User Rating
63 % -3% 65 % +3%
Price (score)
$130 -21% $103 Cheaper.
55 Months -16% 46 Months More recent.
DQ Read
Peak 4K-64Thread Read Speed
367 MB/s +1% 364 MB/s -1%
DQ Write
Peak 4K-64Thread Write Speed
311 MB/s Much faster peak deep queue write.
239 MB/s -30%
AS-SSD Total
AS-SSD Total Score
1,170 Pts Slightly stronger server IO.
1062 Pts -10%
DQ Mixed
Peak 4K-64Thread Mixed IO Speed
78.3 MB/s Slightly faster peak deep queue mixed IO.
68.2 MB/s -15%
ADQ Read
Avg. 4K-64Thread Read Speed
174 MB/s -7% 187 MB/s Slightly faster deep queue read.
ADQ Write
Avg. 4K-64Thread Write Speed
175 MB/s Faster deep queue write.
151 MB/s -16%
ADQ Mixed
Avg. 4K-64Thread Mixed IO Speed
42.5 MB/s -0% 42.6 MB/s +0%
128GB 120GB

The 128GB 840 Pro is a rock solid performer. On release, nearly a year and a half ago, the Pro smashed several speed records. Today, with sequential read/write speeds of 519/438 MBps, the Pro is still one of the fastest SSDs available. One of the Pro's top competitors is Samsungs own, newer 840 Evo. Looking at a raw synthetic speed comparison of the 128GB Pro and Evo is a little misleading. On the face of it the Pro only has a marginal lead over the Evo. This due to the fact that the Evo can only maintain its burst write speed for transfers of up to 3GB, the size of its SLC cache. The Pro on the other hand can sustain higher throughputs indefinitely. The Pro also utilizes MLC which is rated for far more erase cycles than the TLC used in the Evo. Server IO is often continuous and would quickly exhaust the 3GB cache on the Evo but for typical consumer use the Evo will remain within the SLC cache most of the time. [Feb '14 SSDrivePro]


The 120GB Evo, like its 250GB sibling, features a second level Turbowrite cache (TWC). This 3GB block of high speed SLC memory allows the Evo to write data at 370 MB/s, nearly double its normal rate. When the TWC is full write speeds drop by around 50% but since consumers generally write less than 3GB in a typical write operation, the performance drop will rarely be noticed. On the other hand, in a server environment this sort of performance degradation would be unacceptable. Comparing the 120GB and 250GB Evos shows that they have similar performance profiles. The performance equivalence between the different capacities, coupled with the fact that their prices are almost linear, implies that both capacities represent roughly the same value for money. Within its TWC, the 120GB Evo is capable of chart topping burst IO rates and it sits squarely amongst the best performing 120GB drives. [Aug '14 SSDrivePro]


Solid State Drive Rankings (Price vs Performance) May 2017 SSD Rankings.

Welcome to our consumer SSD comparison. We calculate effective speed based on real world performance then adjust by cost per GB to yield a value for money rating. Calculated values don't always tell the whole picture so we check them against thousands of individual user ratings. The customizable table below combines these factors and more to bring you the definitive list of top SSDs. Share your opinion by voting. [SSDrivePro]

How Fast Is Your SSD? (Bench your build) Size up your PC in less than a minute.

Welcome to our freeware PC speed test tool. UserBenchmark will test your PC and compare the results to other users with the same components. You can quickly size up your PC, identify hardware problems and explore the best upgrades.

UserBenchmark of the month

How it works

  • - Download and run UserBenchMark (UBM).
  • - CPU tests include: integer, floating and string.
  • - GPU tests include: six 3D game simulations.
  • - Drive tests include: read, write and mixed IO.
  • - Checks include: 4k Align, NCQ, TRIM, SATA, USB & S.M.A.R.T.
  • - RAM tests include: single/multi core bandwidth and latency.
  • - Reports are generated and presented on
  • - Identify the strongest components in your PC.
  • - See speed test results from other users.
  • - Compare your components to the highest voted in class.
  • - Find the best upgrades.
  • - Share your opinion by voting.

 Frequently Asked Questions

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The Best.
Intel Core i7-7700K $309Nvidia GTX 1070 $368Samsung 850 Evo 250GB $99
Intel Core i5-7600K $229AMD RX 480 $227Samsung 850 Pro 256GB $132
AMD Ryzen 7 1700 $300Nvidia GTX 1060-6GB $230Samsung 850 Evo 500GB $160
Seagate Barracuda 1TB (2016) $45Corsair Vengeance LPX DDR4 3000 C15 2x8GB $127SanDisk Extreme 64GB $33
Seagate Barracuda 3TB (2016) $85G.SKILL Trident Z DDR4 3200 C14 4x16GB $700SanDisk Extreme 32GB $22
Seagate Barracuda 7200.14 1TB $46Corsair Vengeance LPX DDR4 3200 C16 2x8GB $136SanDisk Ultra Fit 32GB $12
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