PCIe gen4 - high quality Amphenol straddle mount slot, 85Ohm PCB, optimal traces
can work in x8 mode with one cable (input near the power plug)
can work in x16 mode with both inputs connected (must be the same CPU host port and lane ordering must be 0-7->8-15, NOT 8-15->0-7, switching the cables will help!)
mandatory 4-Pin EPS/CPU Power connector to supply 12V