Average Bench: 67.3% (597th of 992)

Based on 2,131 user benchmarks.  Models: SAMSUNG SSD PM851 mSATA 256GB, SAMSUNG SSD PM851 mSATA

Above average average bench

The Samsung PM851 mSATA 256GB averaged 32.7% 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 305MB/s
Avg. 4K Random Read Speed 23.4MB/s

Average consistency

The range of scores (95th - 5th percentile) for the Samsung PM851 mSATA 256GB is 40.5%. 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 159MB/s
Avg. Sustained Write Speed 183MB/s

Average Bench

(Based on 2,131 samples)
Min Avg Max
326 Read 420 489
49.7 Write 204 262
84.1 Mixed 159 196
44.3 SusWrite 183 254
53.4% 242 MB/s
Min Avg Max
10.9 4K Read 23.4 34.8
25.7 4K Write 56.2 86.8
14.1 4K Mixed 22.5 30.1
94% 34 MB/s
Min Avg Max
99.8 DQ Read 305 372
51.7 DQ Write 186 257
41.5 DQ Mixed 71.4 83.9
99.9% 187 MB/s
User Benchmarks Bench Sequential Random 4k Deep queue 4k
The fastest SSD (mainstream) averages a speed of 100%
115GB free (System drive)
Firmware: EXT48D0Q
SusWrite @10s intervals: 172 174 170 202 221 207 MB/s
Read 460
Write 215
Mixed 152
SusWrite 191
56% 255 MB/s
4K Read 26.5
4K Write 30.4
4K Mixed 23.9
87% 26.9 MB/s
DQ Read 265
DQ Write 159
DQ Mixed 77.2
94% 167 MB/s
178GB free (System drive)
Firmware: EXT48D0Q
SusWrite @10s intervals: 234 246 252 251 254 228 MB/s
Read 363
Write 142
Mixed 139
SusWrite 244
49% 222 MB/s
4K Read 11.6
4K Write 20.2
4K Mixed 27
63% 19.6 MB/s
DQ Read 296
DQ Write 146
DQ Mixed 80.9
98% 175 MB/s
80GB free (System drive)
Firmware: EXT4AD0Q
SusWrite @10s intervals: 83 55 56 60 59 53 MB/s
Read 314
Write 103
Mixed 101
SusWrite 61.1
32% 145 MB/s
4K Read 11.4
4K Write 11.9
4K Mixed 6.6
32% 9.97 MB/s
DQ Read 152
DQ Write 68.9
DQ Mixed 53.2
55% 91.3 MB/s
2,131 MORE »

 Market Share (See Leaders)

The number of benchmark samples for this model as a percentage of all 12,966,448 SSDs tested.

Typical PM851 mSATA 256GB Builds (Compare 2,757 builds) See popular component choices, score breakdowns and rankings.
Gaming 13%
Tree trunk
Desktop 42%
Speed boat
Workstation 23%

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) March 2019 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.


992 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 i7-8700K $370Nvidia GTX 1070 $364Samsung 850 Evo 250GB $75
AMD Ryzen 5 1600 $120Nvidia GTX 1060-6GB $230Samsung 850 Evo 500GB $105
Intel Core i5-8600K $260Nvidia GTX 1080-Ti $808Samsung 850 Pro 256GB $97
Seagate Barracuda 1TB (2016) $43Corsair Vengeance LPX DDR4 3000 C15 2x8GB $105SanDisk Extreme 64GB $43
Seagate Barracuda 3TB (2016) $85G.SKILL Trident Z DDR4 3200 C14 4x16GB $761SanDisk Extreme 32GB $48
WD Blue 1TB (2012) $45Corsair Vengeance LPX DDR4 3200 C16 2x8GB $110SanDisk Ultra Fit 32GB $12
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