Apple Xserve Memory Upgrade Configurator - choose your Model:

1.33GHz/Dual 1.33GHz
1GHz/Dual 1GHz
G5 2GHz / Dual 2.3GHz (January 2005)
G5 2GHz / Dual 2GHz (January 2004)
Xeon (2006)
Xeon (2008)
Xeon (DDR3) 8-Core
Xeon (DDR3) Quad-Core