Nothing much. RAM is backwards compatible. If OCing the procesor PC3200 will give you a little to work worth at the top end if needed (which is not likely even at 4GHz). PC3200 400MHz. requires slightly more voltage. The MB VR's should have no problem providing the required voltage.
Even installing PC2700 (DDR333) mem is overclocking, and suggested by Intel.
The question is if I install DDR400(pc3200) mem how much overclock, i mean Volt and
what about cooling option, will my Processor fan take care of it without much noise.
What are the implications in long run by OCing.
I am novice to this OC thing, What will be corresponding proceesor performance from 2.66GHz.
What will be temperature?