Just curious, but how does the OS see the Dual and Quad processors? I am assuming that XP sees the dual core as a single processor. If it doesn't then what are you going to run as an OS on a quad core system? XP only supports 2 processors, which I assume means it will run 2 x dual cores. If it's really 4 seperate cores then you will have to run a server OS to fully support them.