Want capacity AND speed? WD's 8TB SSD hailed as 'New King of High Capacity' by reviews but questions remain as to why there are only two such devices on the market

WD Black SN850X 8TB SSD
(Image credit: Western Digital)

Western Digital knows high-capacity drives are a priority for SSD buyers, and it has responded by adding a new 8TB model to its WD Black SN850X lineup.

The SN850X series has been on the market for a couple of years, offering 1TB, 2TB, and 4TB models, but this 8TB version is a recent addition.

Announced in July, the 8TB WD Black SN850X SSD uses the same 8-channel SanDisk controller found in the smaller capacities but swaps out the BiCS 5 flash for BiCS 6 TLC NAND, built using four 2TB packages composed of 1024Gbit BiCS 6 dies stacked 16-high.

New king of high capacity

You might expect this change to make the new drive faster than other models in the series, but it isn’t.

As TweakTown explains in its review of the new drive: “512Gbit BiCS 5 flash is still slightly faster than 1024Gbit BiCS 6 - at least it is when it's behind the same SanDisk controller that has always powered the SN850X series." The drive features a PCIe 4.0 x4 interface and offers sequential read speeds of up to 7,200 MB/s and sequential writes of up to 6,600 MB/s. Random read and write speeds reach up to 1,200,000 IOPS, and it has an endurance rating of 4,800 TBW.

With this new 8TB model, Western Digital finally has a competitor for Phison E18 8TB SSDs, the best-known of which is Sabrent’s Rocket 4 Plus 8TB. In its benchmarks, TweakTown found the WD Black SN850X 8TB SSD landed mid-table in most tests when up against smaller capacity drives but comfortably outperformed the Phison 8TB. That result is no real surprise, as the Phison drive was introduced over two years ago and is now somewhat outdated.

TweakTown declared the WD Black SN850X 8TB SSD the “New King of High Capacity” in its review, awarding it a 95% rating, and noting, “The 8TB capacity point is indeed the rarest of the rare when it comes to consumer NVMe SSDs. To this point, there have been only two of them. Of those two, the WD Black SN850X 8TB is vastly superior as it relates to user experience, or performance that matters."

The WD Black SN850X not only outpaced the Phison 8TB but also undercuts it at $849.99 -several hundred dollars cheaper. The site also noted there’s a version with a heatsink available for $899.99, making it an ideal option for the PlayStation 5 and other high-capacity storage needs.

WD Black SN850X 8TB SSD benchmarks

(Image credit: TweakTown)

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Wayne Williams
Editor

Wayne Williams is a freelancer writing news for TechRadar Pro. He has been writing about computers, technology, and the web for 30 years. In that time he wrote for most of the UK’s PC magazines, and launched, edited and published a number of them too.

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