[guandi]

not very much.. if you have a heatsink *under* the cpu... how are you going to get cold air in there to move the hot air away? imho your wasting your time, but its a nice thought anyway. maybe you should put your eforts into making a waterblock that fits in there, against the mobo and cpu hotspots, i reckon it would be easier trying to find a way to get a small pipe under the zif that getting air in there.