After a ton of speculation, a bit of denial, and a ton of testing we finally have our answer. The thermal interface material change made by Intel when it went from Sandy Bridge to Ivy Bridge is indeed the cause of the excessive temperatures we’ve observed while overclocking. The first accusation was made in late-April by Overclockers.com, however proving it wasn’t easy. The Japanese division of PC Watch somehow managed to remove the integrated heat spreader from a Core i7 3770k, along with the stock binding and grease. They then proceed to replace it with aftermarket alternatives, and the results speak for themselves.
The findings are undisputable. By swapping out the TIM with OCZ Freeze and Coolaboratory Liquid Pro, they were able to lower the temperatures by up to 18% off a stock clocked chip, and a whopping 23% when overclocked from 3.5GHz to 4GHz. Chips with the aftermarket TIM were also able to sustain higher core voltages, which of course will lead to better overclocking potential.
The report concludes that Intel’s decision to move away from the fluxless solder used in Sandy Bridge has unfortunately crippled the overclocking potential of this generation of CPU’s. Its possible Intel may eventually change the design back, however with AMD lagging pretty far behind these days they really don’t have much incentive to do so. Enthusiasts really only have one place to shop for CPU’s these days.
Ivy Bridge is still an amazing push forward performance wise, it’s just unfortunate that the potential for even more is there and we can’t get at it.