PCI Express x16: 3x PCI-E x16 slot
1x PCI-E x1 slot
PCI_E1 Gen PCIe 5.0 supports up to x16 (From CPU)
PCI_E2 Gen PCIe 3.0 supports up to x1 (From Chipset)
PCI_E3 Gen PCIe 4.0 supports up to x4 (From Chipset)
PCI_E4 Gen PCIe 3.0 supports up to x1 (From Chipset)