3 Things to Know About the MSI B550M PRO-VDH M.2 Slot
Only one M.2 slot is available The board has a single M.2 slot, limiting you to one NVMe or SATA M.2 drive.
Supports PCIe 3.0 x4 and SATA 6 Gb/s The slot works with both PCIe 3.0 x4 NVMe drives and SATA 6 Gb/s M.2 SSDs.
Maximum drive length is 2280 The slot accommodates M.2 drives up to 80mm long (2280 form factor).