Mach Speed Viper MK8-939A Via Socket 939 ATX Motherboard and an AMD Athlon 64 3700+ 2.20GHz OEM Processor or Intel DG965RYCK Intel Socket 775 ATX Motherboard with an Intel Core 2 Duo E6300 1.86GHz OEM Processor I don't know the impact of GHz on 2 core CPUs...