Western Digital WD_BLACK SN850X 4TB NVMe internal SSD

Capacity and audience

The WD_BLACK SN850X provides 4TB of internal NVMe storage for gamers and creators who need a single drive to hold large game libraries and project files. It connects through an M.2 slot using a PCIe 4.0 x4 interface.

PCIe 4.0 bandwidth ceiling

Sequential reads reach 7300MB/s and writes reach 6600MB/s, which is the practical throughput limit of the PCIe 4.0 x4 link. Random performance scales to 1200000 IOPS, so queue-depth-heavy workloads saturate the bus before the controller does.

Endurance rating

The drive is rated for 2400 TBW, a figure that determines whether the 4TB capacity will survive sustained write-heavy use such as game installs, video capture or database workloads over the expected service life.