Samsung 980 NVMe SSD vs SanDisk Optimus GX PRO 850X NVMe SSD

The Samsung 980 is the safer, better-documented drive: PCIe Gen3 speeds, a 600 TBW endurance rating and 1.5 million hour MTBF, backed by thousands of owner ratings. The SanDisk Optimus GX PRO 850X is the faster drive on paper, with PCIe Gen4 sequential reads around 7,300 MB/s and writes around 6,600 MB/s, and it comes in a 4 TB capacity. Buy the Samsung for a Gen3 laptop or desktop and for proven reliability; buy the SanDisk if your board supports Gen4 and you move large files or want one big drive.

• Choose the Samsung 980 if your system is PCIe Gen3, you want a single-sided drive that fits thin laptops, and you value a long track record over peak speed.
• Choose the SanDisk Optimus GX PRO 850X if you have a PCIe Gen4 slot and want the fastest sequential transfers or a 4 TB capacity in one drive.