The Western Digital Black SN770 is a solid-state drive in the M.2 2280 form factor, launched on February 2nd, 2022. It is available in capacities ranging from 250 GB to 2 TB. This page reports specifications for the 250 GB variant. With the rest of the system, the Western Digital Black SN770 interfaces using a PCI-Express 4.0 x4 connection. The SSD controller is the 20-82-10081-A1 Polaris MP16+ from WD, a DRAM cache is not available. Western Digital has installed 112-layer TLC NAND flash on the Black SN770, the flash chips are made by Kioxia. To improve write speeds, a pseudo-SLC cache is used, so bursts of incoming writes are handled more quickly. Thanks to support for the fast PCI-Express 4.0 interface, performance is excellent. The Black SN770 is rated for sequential read speeds of up to 4,000 MB/s and 2,000 MB/s write; random IO reaches 240K IOPS for read and 470K for writes.
At its launch, the SSD was priced at 59 USD. The warranty length is set to five years, which is an excellent warranty period. Western Digital guarantees an endurance rating of 150 TBW, a typical value for consumer SSDs.