Average Bench: 100% (5th of 639)

Based on 138 user benchmarks.  Device: VID 1058 PID 25f6 Model: WD My Book Duo 25F6
Poor: 18%Average: 100% Great: 141%

Outstanding average bench

The WD My Book Duo 25F6 20TB averaged 0.4% higher 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 245MB/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 0.69MB/s
Avg. 4K Random Read Speed 7.11MB/s

Average Bench

(Based on 138 samples)
Min Avg Max
30.5 Read 255 344
22.4 Write 245 348
25.6 Mixed 133 209
14.1 SusWrite 241 365
292% 219 MB/s
Min Avg Max
1.38 4K Read 7.11 16.5
1.5 4K Write 3.06 4.31
0.49 4K Mixed 0.69 1.2
154% 3.62 MB/s
User Benchmarks Bench Sequential Random 4k Deep queue 4k
The fastest USB (mainstream) averages a speed of 100%
15TB free, PID 25f6
Operating at USB 3.0 Speed
SusWrite @10s intervals: 366 334 373 368 373 373 MB/s
Read 312
Write 328
Mixed 158
SusWrite 364
394% 291 MB/s
4K Read 6.9
4K Write 3.2
4K Mixed 0.6
155% 3.57 MB/s
17TB free, PID 25f6
Operating at USB 3.0 Speed
SusWrite @10s intervals: 316 321 324 321 322 324 MB/s
Read 288
Write 275
Mixed 152
SusWrite 321
348% 259 MB/s
4K Read 7.9
4K Write 3.4
4K Mixed 1
179% 4.1 MB/s
1TB free, PID 25f6
Operating at USB 3.0 Speed
SusWrite @10s intervals: 197 199 200 196 196 203 MB/s
Read 301
Write 262
Mixed 150
SusWrite 198
295% 228 MB/s
4K Read 8.4
4K Write 2.9
4K Mixed 0.8
157% 4.03 MB/s
2.5TB free, PID 25f6
Operating at USB 3.0 Speed
SusWrite @10s intervals: 225 238 236 258 251 227 MB/s
Read 231
Write 200
Mixed 128
SusWrite 239
266% 200 MB/s
4K Read 2.9
4K Write 2.8
4K Mixed 0.8
133% 2.17 MB/s
138 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.

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  • - CPU tests include: integer, floating and string.
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USB Flash Drive Rankings (Price vs Performance) September 2020 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 i5-9600K $195Nvidia GTX 1660S (Super) $230Crucial MX500 250GB $43
Intel Core i5-9400F $140Nvidia GTX 1650S (Super) $170Samsung 850 Evo 120GB $78
Intel Core i7-9700K $290Nvidia RTX 2070S (Super) $475Samsung 860 Evo 250GB $44
Seagate Barracuda 1TB (2016) $35Corsair Vengeance LPX DDR4 3200 C16 2x8GB $66SanDisk Extreme 64GB $72
WD Blue 1TB (2012) $32Corsair Vengeance LPX DDR4 3000 C15 2x8GB $65SanDisk Extreme 32GB $30
Seagate Barracuda 3TB (2016) $85G.SKILL Trident Z DDR4 3200 C14 4x16GB $649SanDisk Extreme 16GB $28
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