Best card to run in a x16 slot in x4 mode? No dual 8x on this mobo

PCI Express X16 vs X8 vs X4 vs X1 Slot: Difference, Use pcie x4 in x16 slot Any of P27F Series support all of x16, x8, x4 and x6 PCIe Cards by PCIe x16 Slot, and the maximum PCIe lanes are decided by edge connector gold finger pcie 20 x16 slot 1 x PCIe x16 slot Intel® B760 Chipset 1 x PCIe x16 slot 1 x PCIe x1 slot

pcie 20 x1 slot The number of lanes that a PCIe device supports is typically expressed like “x4” for 4 lanes, “x8” for 8 lanes, and so on x1, x2, x4, x8, x16 PCIe Gen 3