PCI Express 4.0 x16: CPU:
1 x PCI Express x16 slot, supporting PCIe 4.0 and running at x16 (PCIEX16)
* For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.
PCI Express 3.0 x16: Chipset:
4 x PCI Express x16 slots, supporting PCIe 3.0 and running at x1 (PCIEX1_1, PCIEX1_3~PCIEX1_5)