SanDisk Optimus GX PRO 8100 SSD vs SanDisk Optimus GX PRO 850X NVMe SSD

The GX PRO 8100 is the faster drive on paper: PCIe Gen5 x4 with sequential reads around 14,900 MB/s, roughly double the 850X's Gen4 ceiling of 7,300 MB/s. That gap only shows up in large sequential transfers and only if your motherboard and CPU have a Gen5 M.2 slot. The 850X is the safer pick for most builds: Gen4 works in far more machines, it runs cooler, and owners rate it well. Both are 4 TB, M.2 2280, NVMe, and use 3D TLC flash, so the real split is interface generation, heat, and platform support.

• Choose the SanDisk Optimus GX PRO 8100 if you have a Gen5-capable motherboard and move huge files, such as video scrubbing, large game installs or big dataset transfers, and you can give it airflow or a heatsink.
• Choose the SanDisk Optimus GX PRO 850X if you are on a Gen4 or older platform, want a proven drive with strong owner ratings, or would rather avoid the heat and power draw of a Gen5 part.