TEST: Western Digital WD_BLACK SN850 1TB M.2 SSD

Technical data
Image
Manufacturer	Western Digital
Model number	WDS100T1X0E-00AFY0
Storage capacity	1024 GB (931 GiB)
pSLC-Cache	285 GB approx.
Read speed	7000 MB/s
Write speed	5300 MB/s
Interface	PCIe 4.0 x4
Connection	M.2 2280
Memory module (NAND)	TLC
DRAM Cache	✓ yes
TBW (Total Bytes Written)	600 Terabyte
Controller	WD 20-82-10034-A1
Price	ca. 127 USD (= 0,12 $ / GB)
Paid link	Buy on Amazon

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Compared to the top performer*

Read speed

94 %

Write speed

76 %

*) Test result evaluated according to AS SSD Score within the same size.

This SSD is PS5 compatible. It can be used as expansion storage in a PlayStation 5 console.

AS SSD Benchmark

Standard performance test

The standard test was performed using a 5 GB file. A total score of 8590 points was achieved.

AS SSD	Read:	Write:
Seq in megabytes per second	5872,31 MB/s	5194,93 MB/s
4K in megabytes per second	75,68 MB/s	211,02 MB/s
4K-64Thrd in megabytes per second	2598,19 MB/s	2963,93 MB/s
Access time in milliseconds	0,018 ms	0,089 ms
Score	3261	3694
Total score	8590

Copy Performance Test

A common everyday situation is simulated here. Three test folders are created:

• ISO (folder with two large files)
• Program (folder with many small files)
• Game (folder with small and large files)

The three folders are copied using the Windows Copy command (the cache remains enabled). The practical test of September 29, 2023 shows the performance for simultaneous write and read operations. The lower the duration, the better the performance.

AS SSD Copy-Benchmark	Transfer rate:	Duration:
ISO two large files	2102,81 MB/s	1,09 s
Program many small files	785,64 MB/s	8,96 s
Game small and large files	1574,80 MB/s	4,39 s

Compression Performance Test

This measures the write and read speed of the Western Digital SSD, depending on the compressibility of the data (according to the manufacturer, these should be 7000 MB/s and 5300 MB/s respectively ).

CrystalDiskMark Benchmark

Here, two sequential and two random performance tests are performed, similar to the ones performed on the AS SSD.

CDM	Read [MB/s]	Write [MB/s]
SEQ1M Q8T1	7033,99	5222,73
SEQ1M Q1T1	4356,48	5230,67
RND4K Q32T16	4092,40	2907,25
RND4K Q1T1	81,14	220,13

HD Tune Pro Endurance test

This is a long term test to make full use of the memory capacity. You can see when a cache is full and the writing performance decreases. A test file of 300 GB was written to the medium. After approx. 285 GB, the pSLC-Cache was full and the performance was throttled.
At least the test file could be read with an average write speed of 6139 MB/s and written with 4504 MB/s.

HD Tune Pro Benchmark

HD Tune writes a 5 GB file to the Western Digital M.2 SSD. The transfer data of the read speed is displayed graphically. The minimum, maximum and average values are also determined. The determined access time and burst rate are also displayed.

ATTO Disk Benchmark

Here, a 256 MB file is written several times to the Western Digital M.2 SSD. The I/O block size varies (from 512 bytes to 64 megabytes). The larger the blocks, the faster they were written and read.

SSD-Z Benchmark

Similar to HD Tune, a 500 MB file is written to the Western Digital M.2 SSD here. The transfer data is displayed. The more constant the line, the better. Unfortunately, the tool does not work correctly above about 5,000 MB/s and no line (and sometimes wrong min and max data) is displayed.

The benchmark test was performed on September 29, 2023.
Information about the test system can be found at the bottom of the home page.
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