Average Bench: 65.6% (697th of 1040)

Based on 4,381 user benchmarks.  Models: SAMSUNG SSD PM851 mSATA 256GB, SAMSUNG SSD PM851 mSATA

Above average average bench

The Samsung PM851 mSATA 256GB averaged 34.4% lower than the peak scores attained by the group leaders. This isn't a great result which indicates that there are much faster alternatives on the comparison list.


Avg. 4K-64Thread Read Speed 322MB/s
Avg. 4K Random Read Speed 23.1MB/s

Average consistency

The range of scores (95th - 5th percentile) for the Samsung PM851 mSATA 256GB is 40.4%. This is a relatively wide range which indicates that the Samsung PM851 mSATA 256GB performs inconsistently under varying real world conditions.


Avg. Sequential Mixed IO Speed 153MB/s
Avg. Sustained Write Speed 169MB/s

Average Bench

(Based on 4,381 samples)
Min Avg Max
319 Read 415 490
45.6 Write 188 261
74.4 Mixed 153 194
39 SusWrite 169 253
51% 231 MB/s
Min Avg Max
11.1 4K Read 23.1 33.7
22.2 4K Write 53.1 81.1
13.2 4K Mixed 22.1 29.8
91.5% 32.8 MB/s
Min Avg Max
154 DQ Read 322 373
47.4 DQ Write 175 257
50.2 DQ Mixed 72.8 84
101% 190 MB/s
User Benchmarks Bench Sequential Random 4k Deep queue 4k
The fastest SSD (mainstream) averages a speed of 100%
102GB free (System drive)
Firmware: EXT48D0Q
SusWrite @10s intervals: 71 60 56 56 57 56 MB/s
Read 450
Write 59.5
Mixed 104
SusWrite 59.3
36% 168 MB/s
4K Read 31.8
4K Write 40.9
4K Mixed 22.7
99% 31.8 MB/s
DQ Read 349
DQ Write 81.3
DQ Mixed 71.5
90% 167 MB/s
106GB free (System drive)
Firmware: EXT48D0Q
SusWrite @10s intervals: 65 53 55 53 54 52 MB/s
Read 458
Write 72
Mixed 97.9
SusWrite 55.3
37% 171 MB/s
4K Read 25.9
4K Write 46.3
4K Mixed 22.9
93% 31.7 MB/s
DQ Read 366
DQ Write 91.6
DQ Mixed 72.5
94% 177 MB/s
4,381 MORE »

 Market Share (See Leaders)

The number of benchmark samples for this model as a percentage of all 38,353,743 SSDs tested.

Typical PM851 mSATA 256GB Builds (Compare 2,149 builds) See popular component choices, score breakdowns and rankings.
Gaming 5%
Tree trunk
Desktop 54%
Workstation 4%
Tree trunk

System: Dell Latitude E7440


Popular PM851 mSATA 256GB systems:

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.
  • - CPU tests include: integer, floating and string.
  • - GPU tests include: six 3D game simulations.
  • - Drive tests include: read, write, sustained write and mixed IO.
  • - RAM tests include: single/multi core bandwidth and latency.
  • - Reports are generated and presented on userbenchmark.com.
  • - Identify the strongest components in your PC.
  • - See speed test results from other users.
  • - Compare your components to the current market leaders.
  • - Explore your best upgrade options with a virtual PC build.
  • - Compare your in-game FPS to other users with your hardware.
  • - Share your opinion by voting.
Solid State Drive Rankings (Price vs Performance) January 2021 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 - User sentiment trumps benchmarks for this comparison.
  • Best value for money - Value for money is based on real world performance.
  • Fastest real world speed - Real World Speed measures performance for typical consumers.


1040 Drives (Compared) Thousands of user benchmarks compiled into one comparison list.

See how consistently different SSDs perform with varying real world conditions. The charts also illustrate overall performance, popularity and rank.

 Frequently Asked Questions

 Best User Rated

The Best.
Intel Core i5-10600K $257Nvidia RTX 3060-Ti $400Crucial MX500 250GB $47
Intel Core i5-9600K $200Nvidia RTX 3070 $500Samsung 850 Evo 120GB $78
Intel Core i5-10400F $161Nvidia GTX 1660S (Super) $240Samsung 860 Evo 250GB $40
Seagate Barracuda 1TB (2016) $43Corsair Vengeance LPX DDR4 3200 C16 2x8GB $79SanDisk Extreme 64GB $72
WD Blue 1TB (2012) $38Corsair Vengeance LPX DDR4 3000 C15 2x8GB $71SanDisk Extreme 32GB $28
Seagate Barracuda 3TB (2016) $85G.SKILL Trident Z DDR4 3200 C14 4x16GB $649SanDisk Ultra Fit 32GB $16
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