WD_BLACK SN7100 4TB NVMe SSD vs SanDisk Ultra SSD

Buy the WD_BLACK SN7100 if you have an M.2 NVMe slot and want speed: it reads up to 7000 MB/s and writes up to 6700 MB/s over PCIe Gen4, roughly twelve times the SATA Ultra's sequential read. The Ultra is a 2.5-inch SATA drive at 560 MB/s read, so it suits older laptops and desktops with no M.2 slot, or bulk storage where SATA speed is enough. Both are 4TB SanDisk drives with 3D NAND; the SN7100 carries a far higher endurance rating and a five-year style warranty typical of WD_BLACK, while the Ultra is the slower, older design.

• Choose the WD_BLACK SN7100 if your board has an M.2 2280 PCIe Gen4 slot and you want the fastest load times and the highest endurance for a 4TB drive.
• Choose the SanDisk Ultra if you only have a 2.5-inch SATA bay, or you want a drop-in drive for an older laptop or desktop.