Will M.2 SSD to SATA III adapter decrease the performance of the M.2 SSD?

Question

After seeing an M.2 SSD to SATA III adapter I got the idea to make older computers/laptops faster by buying some M.2 SSDs, but will using an M.2 SSD adapter reduce the performance/capabilities of the M.2 drive itself? Will older motherboards be able to not limit the full capabilities/performance of the M.2 SSD?

Solution

It depends on the specifications of the M.2 SSD. If it uses the SATA III spec, then there will be no noticeable difference. However, if it uses the PCIe NVMe spec, you will not see NVMe speeds and will be limited to SATA III speeds. If you want NVMe speeds on systems without an M.2 connector, you would have to use a M.2 to PCIe adapter and put it in one of your PCIe slots.

Notes:

SATA III SSDs usually operate between 500MBps and 600MBps maximum. NVMe SSDs usually run from 1GBps upwards (Some nearing 3GBps on sequential reads).