WD Blue SN550 NVMe SSD vs SanDisk 320 SATA SSD 500GB

Buy the WD Blue SN550 for any modern build. It is an NVMe drive on PCIe Gen3 x4, so it reads at up to 2,400 MB/s and writes at up to 950 MB/s, roughly four times the sequential read of the SanDisk 320's 545 MB/s. The SN550 also comes in 250 GB to 2 TB and is rated at 1.75 million hours MTBF, with a 4.7 rating from about 1,500 owners. The SanDisk 320 is a 2.5-inch SATA drive in one 500 GB capacity, and its 4.9 rating rests on only 41 reviews. Pick it only if your board has no M.2 slot or you need a drive for an older laptop or desktop.

• Choose the WD Blue SN550 if your system has an M.2 2280 slot and you want NVMe speed, a slim single-sided drive and a capacity choice from 250 GB to 2 TB.
• Choose the SanDisk 320 if you are upgrading an older machine that only takes a 2.5-inch SATA drive.