I also installed the card on an ASUS board, but according to the mainboard manual my PCIe 3 uses 8x in the slot where it is inserted. The same is also stated on the manufacturer's page "PCI Express 3.0 x16 interface, compatible with PCI Express x8 and x16 slots, support data transfer rates up to 128 Gbps." My x16 slot is occupied by the GPU