WD Black SN850 SSD
Samsung has some serious competition.
It seems like it was just yesterday that we were wondering when traditional HDD manufacturers like Western Digital were going to enter the SSD market. And enter it did. After the acquisition of SanDisk, WD became one of undisputed leaders in the SSD space. Straight up, the SN850 is one of the fastest SSDs we’ve ever tested.
Western Digital is one of a handful of manufacturers that has the capability to design and manufacture its SSDs in-house. This means it doesn’t have to rely on third-party manufacturers or generic firmware. We hope this leads to cost advantages that can be passed on to the consumer, though at the time of writing, the 1TB model we’re reviewing is priced at over $400. That’s too expensive, though we’re sure that will change once the launch phase passes.
The WD SN850 is a standard form factor M.2 2280 (80mm length) NVMe drive that makes use of the now widely adopted PCIe 4.0 x4 interface. It uses WD’s own BiCS (Bit Cost Scaling) 96-layer 3D TLC NAND flash memory. There aren’t many public details on the WD Black G2 controller the drive uses, though there is a 1GB DRAM buffer and SLC caching that both help to maintain top performance. Additional features include S.M.A.R.T. monitoring, trim and garbage collection. Curiously there’s no AES drive encryption, something we noted with the SN750. The five-year warranty and 600TBW endurance rating of the SN750 are carried over to the SN850.
WD deserves credit for its Dashboard SSD management software, particularly the interface. The usual things like monitoring, secure erases and firmware updating are all present. You can also download a copy of the Acronis True Image disk cloning software from the WD website.
We expected the SN850 to perform to a very high level, and we weren’t disappointed. Its random write performance is the best we’ve seen from any SSD. This means it’s a great option for users who frequently write files to the drive, particularly content creators. Its read performance is also good, but its low queue depth performance and IOPS are a bit behind the Samsung 980 Pro. This is what gives an SSD its ‘snappiness’ though at these levels it’s not going to be noticeable. It must be noted that
M.2 PCIe 4.0 drives can get very hot when pushed hard for a sustained period of time. The SN850 doesn’t come with a heatsink, so you’ll be best served by putting it under a motherboard heatsink. If not, you’ll need good airflow. We saw a peak of 68c in an open testbed environment, which means a closed, cramped case could see temperatures a lot higher than that.
There’s no doubt that the SN850 is a very fast drive. Its excellent write performance will appeal to content creators and users that frequently move large amounts of data around. It’s no slouch anywhere else either. The problem is that the similarly excellent Samsung 980 Pro can be found for a much cheaper price. As is almost always the case with a new release SSD, pricing usually decreases over the life of the SKU. If and when that happens, the WD SN850 is sure to take its place alongside the 980 Pro. That alone is a serious achievement.
CHRIS SZEWCZYK
This WD is very fast indeed, but for now the equally impressive Samsung 980 Pro offers much better value.