M vs : What's the Difference?

: h81 motherboard with nvme slot

My PCIe x 16 is filled with my GPU but the PCIe x 4 is free so this seems like the solution Sabrent do a NVMe SSD to PCIe X16X8

m2 slot types 2 slots on the motherboard of the HP Stream Mini The left one is E The Intel SSD is keyed for slots B and M, so it fits in the right slot

m2_1 slot Two types of PCIe slot on an Asus H81M-K motherboard On the contrary, the L-series among others can only support cards using the PCIe standard in the WWAN