Technical Snapshot

The WD Black SN850X 4TB NVMe SSD (Heatsink) is a high-performance M.2 2280 solid state drive built with TLC flash and a PCIe 4.0 x4, NVMe 2.0 interface. It delivers sequential read speeds Up to 7,200 MB/s and sequential write speeds Up to 6,300 MB/s. Random I/O reaches 1,200,000 read IOPS and 1,200,000 write IOPS. The drive offers 4TB of storage, an endurance rating of 2,400 TBW, a 1,750,000 hours MTBF, backed by a 5 years warranty. Part of WD's Black SN850X product line, this drive targets enthusiast gamers, content creators, and workstation builders requiring high-bandwidth NVMe storage.

Use Case: Gaming, content creation, high-bandwidth NVMe storage
Compatibility: M.2 2280 slot, PCIe 4.0 x4, NVMe 2.0-capable motherboard
Category: Internal NVMe SSD — WD Black SN850X

WD SSD

WD Black SN850X

Black SN850X 4TB NVMe SSD (Heatsink)

Name: WD Black SN850X 4TB NVMe SSD (Heatsink)
Brand: WD
SKU: WDS400T2XHE

PCIe 4.0 x4, NVMe 2.0 · M.2 2280 · TLC · Up to 7,200 MB/s Read

Capacity 4TB

Seq Read Up to 7,200 MB/s

Seq Write Up to 6,300 MB/s

Endurance 2,400 TBW

MPNWDS400T2XHE

CategorySolid State Drives

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Performance & Interface

Form FactorM.2 2280

InterfacePCIe 4.0 x4, NVMe 2.0

Sequential ReadUp to 7,200 MB/s

Sequential WriteUp to 6,300 MB/s

Random Read IOPS1,200,000

Random Write IOPS1,200,000

NAND TypeTLC

Endurance (TBW)2,400 TBW

MTBF1,750,000 hours

Warranty5 years

Full Specifications

Data sourced from WD product specifications

Storage
Product Line	Black SN850X
Capacity	4TB
Form Factor	M.2 2280
Interface	PCIe 4.0 x4, NVMe 2.0
NAND Type	TLC
Performance
Sequential Read	Up to 7,200 MB/s
Sequential Write	Up to 6,300 MB/s
Random Read IOPS	1,200,000
Random Write IOPS	1,200,000
Endurance & Reliability
Endurance (TBW)	2,400 TBW
MTBF	1,750,000 hours
Warranty	5 years
Product
Brand	WD
MPN	WDS400T2XHE
Variant	Heatsink
Physical
Weight	8.0 g

Support & Downloads

WD Black SN850X 4TB NVMe SSD (Heatsink) Firmware UpdateLatest firmware · Check WD support

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WD Black SN850X 4TB NVMe SSD (Heatsink) DatasheetPDF · Technical specifications

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Frequently Asked Questions

Is the WD Black SN850X 4TB NVMe compatible with my motherboard?

The WD Black SN850X 4TB NVMe SSD (Heatsink) uses a M.2 2280 form factor with PCIe 4.0 x4, NVMe 2.0 interface. It is compatible with any motherboard that has a matching M.2 2280 slot. This includes AMD AM5/AM4 and Intel LGA 1851/LGA 1700 platforms. PCIe is backward-compatible, so older PCIe generation slots will work at reduced bandwidth.

Can I use the WD Black SN850X 4TB NVMe in a laptop?

Yes, if your laptop has an M.2 2280 NVMe slot. Some laptops use shorter M.2 2230 or M.2 2242 form factors — the WD Black SN850X 4TB NVMe SSD (Heatsink) requires the standard 2280 (80mm) length slot.

What is the endurance rating of the WD Black SN850X 4TB NVMe?

The WD Black SN850X 4TB NVMe SSD (Heatsink) is rated for 2,400 TBW with a 1,750,000 hours MTBF, backed by a 5 years warranty. At typical consumer usage of ~50 GB/day, this provides years of reliable operation.

How fast is the WD Black SN850X 4TB NVMe?

The WD Black SN850X 4TB NVMe SSD (Heatsink) delivers Up to 7,200 MB/s sequential read and Up to 6,300 MB/s sequential write speeds. Random I/O performance: 1,200,000 read IOPS and 1,200,000 write IOPS.

What type of NAND does the WD Black SN850X 4TB NVMe use?

The WD Black SN850X 4TB NVMe SSD (Heatsink) uses TLC flash memory with 4TB storage capacity. TLC NAND offers a good balance of performance, endurance, and cost.

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Product: WD Black SN850X 4TB NVMe SSD (Heatsink)
MPN: WDS400T2XHE
Schemas: Product + BreadcrumbList + FAQPage
Properties: 12 additionalProperty entries
Related: 5 isRelatedTo links