MOSFETS are the components that regulate volatage to the cpu and RAM and other things on the motherboard. Since they regulate voltage, a lot of current is going through them thus they get really hot. the Zalman 7700cu is good for quiet computing. Not that great if you are going to have some high overclocks. I would get a Thermalright SI-120 or XP-120 and a Triblade Delta 120x38mm.