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

Controller: Marvell 88SS9187. Memory: SanDisk 19nm TLC.

Real World Speed
Performance profile from 34,466 user samples
20,836 User Benchmarks
Best Bench: 107% 207GB free
Worst Bench: 58% 92GB free
Poor: 58% Great: 107%
SPEED RANK: 159th / 911
13,630 User Benchmarks
Best Bench: 81% 28GB free
Worst Bench: 47% 186GB free
Poor: 47% Great: 81%
SPEED RANK: 473rd / 911
Effective Speed
Effective SSD Speed
84.6 % Much faster effective speed.
64.1 %
Avg. Sequential Read Speed
494 MB/s Slightly faster read speed.
454 MB/s
Avg. Sequential Write Speed
366 MB/s Much faster write speed.
237 MB/s
4K Read
Avg. 4K Random Read Speed
28.9 MB/s Slightly faster random read.
27.1 MB/s
4K Write
Avg. 4K Random Write Speed
78.8 MB/s Much faster random write.
48.2 MB/s
Avg. Sequential Mixed IO Speed
398 MB/s Much faster mixed IO speed.
234 MB/s
4K Mixed
Avg. 4K Random Mixed IO Speed
22.4 MB/s Much faster random mixed IO.
14.3 MB/s
Peak Sequential Read Speed
523 MB/s Slightly faster peak read speed.
498 MB/s
Peak Sequential Write Speed
496 MB/s Much faster peak write speed.
340 MB/s
4K Read
Peak 4K Random Read Speed
36.1 MB/s 36.6 MB/s +1%
4K Write
Peak 4K Random Write Speed
112 MB/s Much faster peak random write.
76.6 MB/s
Peak Sequential Mixed IO Speed
509 MB/s Much faster peak mixed IO speed.
331 MB/s
4K Mixed
Peak 4K Random Mixed IO Speed
28.9 MB/s Much faster peak random mixed IO.
20.8 MB/s
Market Share
Based on 6,060,410 SSDs tested.
Market Share
Market Share (trailing 30 days)
0.34 % 0.45 % Much higher market share.
Value For Money
37.2 % 74.1 % Hugely better value.
User Rating
UBM User Rating
63 % 64 % +2%
Price (score)
$290 $75 Much cheaper.
65 Months 42 Months Much more recent.
DQ Read
Peak 4K-64Thread Read Speed
368 MB/s Slightly faster peak deep queue read.
349 MB/s
DQ Write
Peak 4K-64Thread Write Speed
322 MB/s Much faster peak deep queue write.
206 MB/s
AS-SSD Total
AS-SSD Total Score
1,185 Pts Stronger server IO.
980 Pts
DQ Mixed
Peak 4K-64Thread Mixed IO Speed
90.4 MB/s Much faster peak deep queue mixed IO.
51.4 MB/s
ADQ Read
Avg. 4K-64Thread Read Speed
195 MB/s Slightly faster deep queue read.
175 MB/s
ADQ Write
Avg. 4K-64Thread Write Speed
194 MB/s Much faster deep queue write.
130 MB/s
ADQ Mixed
Avg. 4K-64Thread Mixed IO Speed
53 MB/s Much faster deep queue mixed IO.
31.1 MB/s
256GB 240GB

The 840 Pro is stunning. Samsung have created a completely in-house package including both the controller and their own new 21nm toggle mode NAND. On release (Oct '12) this was the fastest performing deep queue depth consumer grade SSD available. Fast forward six months (Apr '13) and the 840 Pro still holds both the random read/write deep queue depth speed records of 384 MB/s and 326 MB/s, impressive considering how fast the SSD space tends to move. There are no obvious weaknesses, in-fact the 840 pro takes first place in nearly all of the speed categories and is only seriously rivalled by one drive, the OCZ Vector. To conclude, in terms of both outright performance, particularly server orientated, and value for money the 256GB and 128GB 840 Pros are amongst the top handful of drives currently available. [Jun '13 SSDrivePro]


The Sandisk Ultra II sits above Sandisk's Ultra Plus and below their Extreme Pro. The Ultra Plus would probably have been phased out completely were it not for its continued success within budget space. The Ultra II is the first Sandisk drive to utilize cheaper (and slower) TLC NAND. Similarly to the Extreme Pro, the Ultra II utilizes an nCache which operates a portion of the NAND in simulated SLC mode. This strategy also matches the one employed by Samsung's now 14 months old Evo. Comparing the Ultra II and Evo shows broad performance equivalence which given the Ultra II's 15% price discount makes it the better choice today. That said it's probably worth waiting for the release of the 850 Evo which will pack another 14 months of Samsung's market leading R&D and will probably steal the show. [Sep '14 SSDrivePro]


Solid State Drive Rankings (Price vs Performance) March 2018 SSD Rankings.

Welcome to our 2.5" and M.2 SSD comparison. We calculate effective speed for both SATA and NVMe drives based on real world performance then adjust by current prices per GB to yield a value for money rating. Our calculated values are checked against thousands of individual user ratings. The customizable table below combines these factors to bring you the definitive list of top SSDs. [SSDrivePro]


Group Test Results

  • Best user rated - Sometimes benchmarks get it completely wrong...
  • Fastest real world speed - Real World Speed measures performance for typical consumers.
  • Best value for money - Value for money is based on real world performance, price and capacity.
  • Raw speed comparison - Raw speed readings.
  • Details ordered by value - Detailed performance stats ordered by overall value for money.
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

 Best User Rated

The Best.
Intel Core i7-8700K $330Nvidia GTX 1070 $447Samsung 850 Evo 250GB $85
Intel Core i7-7700K $290Nvidia GTX 1060-6GB $335Samsung 850 Evo 500GB $150
AMD Ryzen 5 1600 $188AMD RX 480 $400Samsung 850 Pro 256GB $139
Seagate Barracuda 1TB (2016) $44Corsair Vengeance LPX DDR4 3000 C15 2x8GB $190SanDisk Extreme 64GB $44
Seagate Barracuda 3TB (2016) $80G.SKILL Trident Z DDR4 3200 C14 4x16GB $931SanDisk Extreme 32GB $23
Seagate Barracuda 2TB (2016) $60Corsair Vengeance LPX DDR4 3200 C16 2x8GB $216SanDisk Extreme 16GB $18
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