Phosho510, the Front Side Bus is built in mobo's. The FSB speed, is the speed witch it transfer data from the FSB to the cpu. AMD64 do not have FSB, because its built in the processor itself. This means that AMD64, does not have to waste time communicating with the mobo's FSB, since its built in the processor. So AMD64 has no FSB, its a term people can only use for other processors, like intel.