What Should to Do With Extra PCIe Slots?

Can I plug in a PCIe x4 card into a PCIe x16 slot? : rbuildapc pcie x4 in x16 slot If you have the option of multiple slots where at least one supports PCIe, it's worth considering your secondary slot for an SSD upgrade When combined pcie slot configuration gen1 gen2 gen3 PCI Express Expansion · Five PCIe Gen 4 x16 Slots One PCIe x16 Slot for Target Cable Adapter; Four PCIe x16 Slots for Add-in Card · ATX

pcie 20 x16 slot 1) First is simply looking at the motherboard, many times printed on the PCB near the PCIE slot is the actual X4 or X16 or whatever it happens