Intel has as yet to offer a full explanation as to why it changed the way its interfacing the IHS with the CPU die on its Ivy Bridge processors and previous reports weren't clear on how much of an effect Intel's move to using thermal grease had on the actual cooling performance. Thankfully Japanese website Impress PC Watch has come to the rescues and done some testing by itself and the publication has clearly proven that Intel's thermal interface material isn't up to scratch.
Ivy Bridge proven to suffer from poor thermal grease by VR-Zone.com