PCIe x8 Gen3

You can put anything smaller than the slot in just fine It's the PCI-e bracket screw that really holds things into place I'd get the newest

PCI Express Riser Card x8 to x16 Left Slot Adapter for 1U Servers

pcie m2 slot What should be: The PCIe spec states that all slots start at 1x and negotiate how many lanes they can use and what clock speed

pcie 3 slot The adapter card converts the 8X socket on the motherboard to the 16X connector, which greatly improves the application of the motherboard No driver, no jumper