IT Pro is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more

WD Black SN850 review: A PCIe 4 powerhouse

A lightning-fast SSD that comes with a selection of great add-ons – and doesn’t cost the earth

A photograph of the WD Black SN850
Price
£140 exc VAT (1TB)
  • Outstanding speeds
  • Decent value
  • Useful bundled software
  • Won’t hit top speeds with older systems

If you’re upgrading or building a PC, the WD Black SN850 makes a superb system drive. It takes advantage of the huge bandwidth of the PCI Express Gen4 bus to offer performance rival SSDs can’t match: in our tests it achieved a sequential read speed of almost 6GB/sec, and topped 5GB/sec when writing.

Multi-threaded performance is excellent too. In AS SSD’s 64-thread random-access test, the SN850 kept up a read speed of 2,906MB/sec and a write rate of 2,805MB/sec. In both of the PCMark storage benchmarks it achieved solid first-place rankings, scoring 3,502 in the system disk test and 5,984 as a data disk.

Despite these amazing figures, the SN850 is pretty affordable. True, the 1TB model we tested costs around twice as much as WD’s budget Blue SN550 drive, working out to 18p per gigabyte - but it’s hard to complain about that when you’re getting more than double the performance. There’s also a 500GB model for £80 inc VAT, while the 2TB capacity can be had for £340.

Uniquely, WD also offers variants of all SN850 models with integrated heatsinks to ensure things stay fast and stable during heavy workloads. This adds a lot to the price – the 1TB model costs £234 – and we’re not convinced it’s necessary as the standard drive romped through the intensive PCMark benchmarks without a hitch.

Whichever model you go for, you get a custom edition of Acronis True Image, licensed for five years on both Windows and macOS. It’s an excellent add-on that can simplify the process of cloning your old system drive onto the new SSD, and take care of backups once you’re up and running.

Note that the phenomenal performance of the WD Black SN850 is enabled by the PCI Express Gen4 interface. If you install it in an older PC using PCI Express Gen3 it will still work, but in this configuration we saw read speeds peak at 3,091MB/sec, while the overall system drive score fell to 2,883. At that point, cheaper alternatives like the £114 Kingston KC2500 start to look tempting.

If your motherboard supports PCIe Gen4, however, splash out on the WD Black SN850. It’s the fastest drive around, while the bundled software makes it easy to install and use.

WD Black SN850 specifications

Capacity

1TB

Cost Per Gigabyte

18p

Interface

PCIe 4

Claimed Read

2,400MB/sec

Claimed Write

1,950MB/sec

Warranty

5yr

Featured Resources

Big data for finance

How to leverage big data analytics and AI in the finance sector

Free Download

Ten critical factors for cloud analytics success

Cloud-native, intelligent, and automated data management strategies to accelerate time to value and ROI

Free Download

Remove barriers and reconnect with your customers

The $260 billion dollar friction problem businesses don't know they have

Free Download

The future of work is already here. Now’s the time to secure it.

Robust security to protect and enable your business

Free Download

Most Popular

How to secure your hybrid workforce
Advertisement Feature

How to secure your hybrid workforce

23 Sep 2022
The human brain is far more complex than AI researchers imagine
artificial intelligence (AI)

The human brain is far more complex than AI researchers imagine

17 Sep 2022
Why collaboration is key to digital transformation
Sponsored

Why collaboration is key to digital transformation

13 Sep 2022