Western Digital unveiled the WD Blue SN550 line of M.2 NVMe SSDs. A successor to the WD Blue SN500, the SN550 is updated with a new controller that utilizes PCI-Express 3.0 x4 (compared to just x2 on the SN500). Designed in-house by WD and SanDisk, the controller is based on the same architecture as the one that drives the WD Black SN750, but is DRAM-less, and has fewer flash channels. Speaking of which, WD deployed 96-layer 3D TLC NAND flash, and wants the drive to compete in pricing with QLC NAND-based drives such as the Crucial P1. The 250 GB variant is priced at USD $54, the 500 GB variant $65, and the 1 TB variant $99.

All three variants take advantage of the increased PCIe bandwidth to offer sequential read speeds of up to 2,400 MB/s (the SN500 capped out at 1,700 MB/s). Write speeds vary, with the 250 GB variant offering up to 950 MB/s, the 500 GB variant up to 1,750 MB/s, and the 1 TB variant up to 1,950 MB/s. Endurance figures (TBW) of the three variants are rated at 150 TB for the 250 GB variant, 300 TB for the 500 GB variant, and 600 TB for the 1 TB variant. An interesting design choice with these drives is pushing the NAND flash chip and the controller as far apart on the PCB as possible, for less concentration of heat. All three models are backed by 5-year warranties.