WD Black SN850X review: the fast SSD for gamers

Firmly branded as one of the most popular storage solutions in the gaming market, Western Digital's Black range is back with the SN850X, a versatile model aimed at the console and PC audience. Available in 1 TB, 2 TB, 4 and 8 TB versions, it is the 2 TB model that we are examining today. Priced around €120, it is in the same price bracket as other well-known SSDs in the segment, such as the Samsung 990 Pro.

The announced performances are also standard for a PCIe Gen4 SSD of this level. The WD Black SN850X actually claims 7.3 GB/s reading and 6.6 GB/s sequential writing, more than enough to enjoy the latest AAA games without endless loading times.

SLC cache management

On our dynamic cache stress test, the SN850X performed up and down, literally. This WD Black SSD maintained a throughput of 5.3 GB/s on 30% of its capacity before observing an initial drop… which would continue gradually, until zigzagging definitively from 40%. An average result, and if consistency is not its strong point, the median speed of 3.4 GB/s is honorable. Let us remember if necessary that this benchmark specific to the AIDA64 software is particularly intensive and in no way reflects “normal” use of the SSD. Unless writing down your entire storage is part of your habits, and in this case, we will be careful not to judge you.

Thermal management

Under our thermal probe, the WD Black SN850X does not seem to suffer from any particular overheating, even without a heat sink, with a peak at 72.4°C measured during the benchmark. This temperature stabilizes around 39°C during periods of calm. However, in the context of prolonged intense use, from a stronger on long sessions of gamingthe installation of a heatsink is highly recommended if your motherboard is not already equipped with one.

Performances

As promised, the performance of the WD Black SN850X proved to be particularly consistent with the manufacturer's technical sheet during our sequential throughput benchmark on the CrystalDiskMark software. We thus indeed observe 7307 MB/s in reading and 6379 MB/s in writing, a little more than the figures brandished at the start.

But things get bad when it comes to our measurement of IOPS value, or the number of input/output operations. The SN850X remains far from some of its more efficient colleagues in reading. Where the Samsung 990 Pro and the Kingston Fury Renegade easily exceed a million readings, the SN850X falls around 800,000, well below the brand's claims (1.2 million). It is nevertheless particularly efficient in writing, exceeding one million, even above the Samsung 990 Pro.

Finally, our manual copy throughput test once again highlights the SN850X. The copy of our 27 GB file was carried out without problem and the SSD displayed a nice cruising speed of 3.4 GB/s.