PCI Express 3.0 x16: 4 x PCIe 3.0 x16 slots, support up to 3-way mode- 1-way mode: x16/ x0/ x0/ x0- 2-way mode: x16/ x16/ x0/ x0*, 16/ x8/ x0/ x0**- 3-way mode: x16/ x16/ x0/ x8*, x8/ x8/ x8/ x0*** For the CPU that supports 40 PCIe lanes** For the CPU that supports 28 PCIe lanes