Average Bench: 99.8% (5th of 639)

Based on 65 user benchmarks.  Device: VID 1058 PID 25f6 Model: WD My Book Duo 25F6
Poor: 14%Average: 99.8% Great: 137%

Excellent average bench

The WD My Book Duo 25F6 20TB averaged just 0.2% lower than the peak scores attained by the group leaders. This is an excellent result which ranks the WD My Book Duo 25F6 20TB near the top of the comparison list.


Avg. Sequential Write Speed 250MB/s
Avg. Sustained Write Speed 241MB/s

Terrible consistency

The range of scores (95th - 5th percentile) for the WD My Book Duo 25F6 20TB is 123%. This is a particularly wide range which indicates that the WD My Book Duo 25F6 20TB performs inconsistently under varying real world conditions.


Avg. 4K Random Mixed IO Speed 0.65MB/s
Avg. 4K Random Read Speed 6.36MB/s

Average Bench

(Based on 65 samples)
Min Avg Max
24.5 Read 258 334
16.3 Write 250 349
22 Mixed 132 165
12.3 SusWrite 241 364
293% 220 MB/s
Min Avg Max
1.45 4K Read 6.36 10.7
1.23 4K Write 2.88 3.4
0.36 4K Mixed 0.65 0.97
144% 3.3 MB/s
User Benchmarks Bench Sequential Random 4k Deep queue 4k
The fastest USB (mainstream) averages a speed of 100%
9TB free, PID 25f6
Operating at USB 3.0 Speed
SusWrite @10s intervals: 360 365 373 368 371 365 MB/s
Read 310
Write 305
Mixed 138
SusWrite 367
377% 280 MB/s
4K Read 6
4K Write 3.2
4K Mixed 0.6
152% 3.27 MB/s
1TB free, PID 25f6
Operating at USB 3.0 Speed
SusWrite @10s intervals: 204 198 208 214 211 211 MB/s
Read 264
Write 287
Mixed 140
SusWrite 208
299% 225 MB/s
4K Read 4.5
4K Write 3.1
4K Mixed 0.6
142% 2.73 MB/s
65 MORE »
How Fast Is Your USB? (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.
USB Flash Drive Rankings (Price vs Performance) September 2019 USB Rankings.

We highlight the best USB flash drive in terms of balanced performance and value for money using current prices, sequential read, sequential write , 4k read and 4k write speed. The speeds are combined to form a single effective speed which measures performance for tasks such as copying photos, music and videos. Effective speed is adjusted by current price and capacity to yield value for money. Finally thousands of individual user ratings are used to validate our benchmark figures. [USBFlashPro]


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.


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

See how consistently different USBs 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 i5-9400F $140Nvidia GTX 1660 $220Samsung 850 Evo 250GB $70
Intel Core i5-9600K $225Nvidia GTX 1660-Ti $275Samsung 850 Evo 500GB $90
Intel Core i7-9700K $350Nvidia RTX 2060S (Super) $429Samsung 850 Pro 256GB $230
Seagate Barracuda 1TB (2016) $44Corsair Vengeance LPX DDR4 3000 C15 2x8GB $70SanDisk Extreme 64GB $88
WD Blue 1TB (2012) $37G.SKILL Trident Z DDR4 3200 C14 4x16GB $799SanDisk Extreme 32GB $48
Seagate Barracuda 3TB (2016) $64Corsair Vengeance LPX DDR4 3200 C16 2x8GB $73SanDisk Extreme 16GB $24
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