Learn about PCI Express (PCIe) adapters and slots.
PCI Express (PCIe) adapters use a different type of slot than Peripheral Component Interconnect (PCI) and Peripheral Component Interconnect-X (PCI-X) adapters. If you attempt to force an adapter into the wrong type of slot, you might damage the adapter or the slot. A PCI adapter can be installed in a PCI-X slot, and a PCI-X adapter can be installed in a PCI adapter slot. A PCIe adapter cannot be installed in a PCI or PCI-X adapter slot, and a PCI or PCI-X adapter cannot be installed in a PCIe slot. The following illustration shows an example of a PCI-X adapter (A) next to a PCIe 4x (B) adapter.
PCIe adapters and slots come in 4 different sizes: 1x, 4x, 8x and 16x. Smaller size adapters will fit in larger slots, but larger size adapters will not fit in smaller slots. The following table shows PCIe slot compatibility.
1x slot | 4x slot | 8x slot | 16x slot | |
---|---|---|---|---|
1x adapter | Supported | Supported | Supported | Supported |
4x adapter | Not supported | Supported | Supported | Supported |
8x adapter | Not supported | Not supported | Supported | Supported |
16x adapter | Not supported | Not supported | Not supported | Supported |