The 650W Xserve Power Supply Kit from Apple can be used as a replacement or supplemental power supply for the Xserve with Intel Quad Xeon CPU. The Xserve ships with one 650W power supply, with the ability to house two. Adding a second power supply adds redundancy to the Xserve; if one power supply fails, the other will continue to power the computer. This unit can also be used to replace a failed power supply.