Factory heatsink
WD BLACK SN850X 4TBNo
WD BLACK SN850X 4TB with heatsinkYes
SN850X: with or without a heatsink?
Editorial specification comparison · checked 23 October 2026
The 4 TB SN850X has two physically distinct variants. Manufacturer sequential limits and TBW are equal, but the heatsink version is taller. Its MPN ends in XHE rather than X0E.
A laptop, console or motherboard can impose cooling and height requirements. Check before stacking two cooling solutions. Read the host manual and inspect the existing M.2 cover mounting.
This is not a measured temperature or noise test. Use dimensions to exclude unsuitable variants, then compare the current delivered total for the exact version you need.
Compare all specification differences ⇄What changes?
The differences at a glance
Manufacturer facts for these exact variants. The order does not declare a performance winner.
Drive height, up to
WD BLACK SN850X 4TB3.88 mm
WD BLACK SN850X 4TB with heatsink10.31 mm
BLACK SN850X 4TB: 3 unknown fields · BLACK SN850X 4TB with heatsink: 3 unknown fields. Unknown does not mean absent.
Compare capacity and cache, not just peak speed
Manufacturer speeds are maxima under stated test conditions. They do not show sustained writing after the cache fills. TBW is a write-endurance warranty limit, not a predicted failure date; time limits also apply. Check M.2 length, interface and heatsink clearance in the host manual. Price per TB uses nominal decimal capacity and a confirmed delivered total.