PC World - USA (2021-01)

JANUARY 2021 PCWorld 55

now are PCIe 4;

however, we’ll

continue to

include legacy

PCIe 3 testing,

as most users

are still using

the older

version of the high-speed bus.

The SN850 we tested was a

2TB model, while the Samsung 980

Pro to which we compare it was 1TB. While

neither drive slowed down during the long

write, higher-capacity drives have more

NAND to play with, which can help with

caching decisions.

The 2TB SN850 that I tested turned in

great numbers, trading wins with the 1TB

Samsung 980 Pro. The SN850 prevailed in

WD; go.pcworld.com/wd14), 1TB ($249.29
at Amazon; go.pcworld.com/am22), and
2TB (the capacity we tested, $449.99 at
Amazon; go.pcworld.com/am44). That’s
pricier than the average entry-level drives, but
in the same ballpark with the Samsung 980
Pro. DDR4 cache is used to the tune of about
500MB for 500GB, 1GB for the 1TB, and just
over 2GB for the 2TB drive.
The SN850 is rated for 300TBW
(TeraBytes that may be Written over the life of
the drive) for every 500GB of capacity, and
warrantied for five years. I’ve never heard of a
vendor backing off the warranty unless you’re
drastically over the TBW limit.

PERFORMANCE
The SN850 is a PCIe 4 drive, which means
you get a nice boost in performance in
systems that support it (late-Gen Ryzen,
upcoming Intel [go.pcworld.com/lryz]). Most
of the SSDs showing up on our door right

CrystalDiskMark 6 rates the WD Black SN850

as slightly faster writing, and quite a bit slower

reading than the Samsung 980 Pro.

Sequential Write (Q=32, T=1)

5,188

3,892

5,221

CrystalMark 6

MBps

WD Black SN850 PCIe 4 Samsung 980 Pro PCIe 4

Seagate FireCuda 520 PCIe 4 WD Black SN850 PCIe 3

3,336

Sequential Read (Q=32, T=1)

7, 1 2 9

4,525

6,284

3,558

LONGER BARS INDICATE BETTER PERFORMANCE

WD’s Black SN850 is a very fast PCIe 4 drive and
especially adept at very long sustained writes.