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 2 TB 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 Toshiba. To improve write speeds, a pseudo-SLC cache is used, so bursts of incoming writes are processed more quickly. The cache is sized at 740 GB. Copying data out of the SLC cache (folding) completes at 560 MB/s. 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 5,150 MB/s and 4,850 MB/s write; random IOPS reach up to 650K for reads and 800K for writes.
At its launch, the SSD was priced at 269 USD. The warranty length is set to five years, which is an excellent warranty period. Western Digital guarantees an endurance rating of 1200 TBW, a typical value for consumer SSDs.