Asus LGA775,INTEL P43+ICH10,4DDR3 Socket - Intel Socket 775 Supported - Intel Core 2 Quad, Core 2 Extreme, Core 2 Duo, Pentium dual-core, Celeron dual-core, and Celeron Processors Front Side Bus - 1600(O.C)/1333/1066/800MHz Memory - 2x DIMM 4GB; DDR2 1066/800/667MHz Non-ECC, Dual-Channel, Unbuffered Memory PCI Slots - 1x PCI Express x16, 1x PCI Express x1, 2x PCI