M.2 slots don&#x27;t make much sense for servers, at least if you&#x27;re trying to take advantage of the performance benefits possible with a PCIe interface. Current M.2 drives aren&#x27;t even close to saturating the PCIe 3.0 x4 link but they&#x27;re severely thermally limited for sustained use and they&#x27;re restricted in capacity due to lack of PCB area. Server SSDs should stick with the traditional half-height add-in card form factor with nice big heatsinks.