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WD_BLACK SN850X 4TB NVMe SSD - M.2 2280, Up to 7,300 MB/s Read speeds, Up to 6,300 MB/s write speeds, Gaming Expansion, High Performance Internal Solid State Drive - WDS400T2X0E
Sandisk

Sandisk WD_BLACK SN850X 4TB NVMe SSD (WDS400T2X0E)

Bottom line: The Sandisk WD_BLACK SN850X 4TB NVMe SSD ($783.34 on Amazon as of 2026-10-20 20:20 UTC): Up to 7,300 MB/s read and 6,300 MB/s write on the 4TB model; main trade-off: sandisk lists it as replaced by a newer generation drive.

$783.34

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By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014. For SSDs and PC storage upgrades, synthesises manufacturer specs and independent reviews rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference.

*Price sourced from Amazon.com. Last updated 2026-10-20. Price and availability subject to change.

Pros & Cons

Pros

  • ✓ Up to 7,300 MB/s read and 6,300 MB/s write on the 4TB model
  • ✓ 4TB holds a dozen-plus 100-200GB AAA installs
  • ✓ Sandisk TLC 3D NAND rather than cheaper QLC
  • ✓ M.2 2280 fits standard desktop boards and expansion bays

Cons

  • ✗ Sandisk lists it as replaced by a newer generation drive
  • ✗ PCIe Gen4 interface, not Gen5
  • ✗ Rated speeds apply to 1TB-4TB models, not every capacity
  • ✗ No heatsink specified, so board or case cooling matters

Manufacturer description

This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX PRO 850X NVMe SSD TRANFORM YOUR PC: Insane speeds up to 7,300MB/s (1TB - 4TB models) deliver top-tier performance with ridiculously short load times for your gaming PC or workstation — for the elite experience you’ve been waiting for. MORE ROOM FOR MORE GAMES: Capacities up to 8TB built with SANDISK TLC 3D NAND, means you get to keep more games at the ready — and get into the action even faster.

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SpecPicks Verdict

SpecPicks scored Sandisk WD_BLACK SN850X 4TB NVMe SSD using a rating × review-volume × price-fit model applied to published specs and reviews across the ssds & storage category. Sandisk's ssds & storage lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for ssds & storage of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Frequently Asked Questions

How fast is the WD_BLACK SN850X 4TB?

Sandisk rates the 1TB through 4TB models at up to 7,300 MB/s sequential read and up to 6,300 MB/s sequential write over PCIe Gen4.

Will the SN850X fit my motherboard?

It is an M.2 2280 NVMe drive, the standard length used by nearly all desktop motherboards and many gaming expansion bays. Confirm your board has a free M.2 slot.

Is 4TB enough for a game library?

Yes for most builds. Modern AAA titles commonly install at 100-200GB, so 4TB holds roughly a dozen or more plus your OS and applications.

What kind of NAND does the SN850X use?

Sandisk builds it with TLC 3D NAND, and the SN850X family scales up to 8TB if you need more capacity than the 4TB model.

Is this drive still current?

Sandisk notes the SN850X has been replaced by a newer generation. It remains widely reviewed, but check the listing for current availability and warranty terms.

Key Features

  • This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX PRO 850X NVMe SSD
  • TRANFORM YOUR PC: Insane speeds up to 7,300MB/s (1TB - 4TB models) deliver top-tier performance with ridiculously short load times for your gaming PC or workstation — for the elite experience you’ve been waiting for.
  • MORE ROOM FOR MORE GAMES: Capacities up to 8TB built with SANDISK TLC 3D NAND, means you get to keep more games at the ready — and get into the action even faster.

Full Specifications

Size4TB
BrandSandisk
ColorBlack
ModelWDS400T2X0E
Warranty5 year limited warranty
UnitCount1
ReleaseDate2022-08-03T00:00:01Z
ManufacturerSandisk Technologies, Inc.
ItemPartNumberWDS400T2X0E
Full listing titleWD_BLACK SN850X 4TB NVMe SSD - M.2 2280, Up to 7,300 MB/s Read speeds, Up to 6,300 MB/s write speeds, Gaming Expansion, High Performance Internal Solid State Drive - WDS400T2X0E

Ready to buy?

WD_BLACK SN850X 4TB NVMe SSD - M.2 2280, Up to 7,300 MB/s Read speeds, Up to 6,300 MB/s write speeds, Gaming Expansion, High Performance Internal Solid State Drive - WDS400T2X0E is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

Buy on Amazon — $783.34

*Price sourced from Amazon.com. Last updated 2026-10-20. Price and availability subject to change.

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WD_BLACK SN850X 4TB NVMe SSD - M.2 2280, Up to 7,300 MB/s Read speeds, Up to 6,300 MB/s write speeds, Gaming Expansion, High Performance Internal Solid State Drive - WDS400T2X0E
$783.34
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