Well the P5k deluxe supports DDR2 1066 straight out of the box so all you do is select 1066 in the bios, this means that you will have faster ram and a faster system has I was told that Intel's CPUs need the speed more then they need the timings and by the way my E6600 is sitting at 3.0ghz with 1066 ram and with quad core I would think you will need the extra speed