WD Blue SN5100 NVMe SSD vs SanDisk 520 SATA SSD

Buy the WD Blue SN5100 for any machine with an M.2 slot: it is a PCIe Gen 4 NVMe drive with sequential reads up to 7,100 MB/s, roughly twelve times the SanDisk 520's 560 MB/s ceiling. The SanDisk 520 is a plain 2.5-inch SATA drive, so it suits older laptops and desktops with no M.2 slot, or a secondary bay. Both carry a 4.8 rating, but the WD has far more ratings behind it. The SN5100's weakness is its DRAM-less HMB design, which can slow sustained writes; the SATA drive avoids that debate by being slow everywhere.

• Choose the WD Blue SN5100 if your laptop or desktop has an M.2 2280 slot and you want Gen 4 NVMe speed for large files, games and project folders.
• Choose the SanDisk 520 if you have only a 2.5-inch SATA bay, or you want a simple drop-in drive for an older machine.