PCI X1 X1e x1 2.1 1Gbps Single Port Ethernet Desktop Adapter is compatible with PCI X1 X1e x4,x8,x16 slot. System I/O is no longer the bottleneck of network applications. In the networking connections, PCI X1 X1 Express dedicated input /output (I / O) bandwidth to ensure the network Card to use the superior performance without taking up bus bandwidth.