I heard a rumor that the IVy Bridges have heat issues compared to Sandy and Haswell. Not sure if it's just a rumor, but I've been trying to OC my 3570k and can't do it with a 212 EVO, yet I see others getting high OC with that same heatsink on sandy. Even at stock, I'm maxing out at 65C. AS5 and redoing the paste hasn't helped.