I’ve got a Supermicro X11SSV motherboard with an mPCIE slot, and I’ve got a Lenovo Chromebook motherboard with an M.2 wifi card slot. Ideally I’d like to add 2 more sata ports to the Supermicro board, and I’d like to use a aliexpress M.2 to RJ45 adapter on the Chromebook. The problem is I can’t find consistent information on the speeds of these ports. It doesn’t say in either of the manuals, and from googling it seems that m.2 slots sometimes do PCIE x1 and sometimes USB 2.0, and that mPCIE is just another name for mSATA.
Does anyone have any info on how to determine what kind of speeds the ports do? Or how to determine it on a case by case basis? Thanks.


Make sure it is of the right kind. M.2 Wi-Fi slots are key E, M.2 SSD slots are key M (mostly) and cards made for 1 kind does not fit the other.
If the slot is for Wi-Fi it should have PCIe as that is what most Wi-Fi modules connect to. USB is used for Bluetooth mostly.