so i have a dell OEM 4550 dimension....it has a Pentium 4 2.00ghz in it,the socket type is 478......can i upgrade it to a Pentium 4 3.00ghz 478 socket?? i have a bigger fan replacement but will the motherboard accept a CPU of the same type just different clock speeds? http://support.dell.com/support/edocs/systems/dim4550/ thank guys!!!