Published in Processors
Possible reason for Ivy Bridge heat problem explained
by Slobodan Simic on27 April 2012
TIM paste instead of solder under IHS
It has been pretty much confirmed, even by Intel, that Ivy Bridge runs a whole lot hotter than Sandy Bridge when overclocked and it appears that the reason for it was hiding under the Integrated Heat Spreader all along. It appears that Intel decided to use TIM paste rather than fluxless solder which is a much better heat conductor.
As there has always been a possibility that some Ivy Bridge CPU would die during testing, it was only a matter of time before someone took the IHS off just to have some fun and see the CPU die in its glory. The heat problem was usually attributed to either the fact that power density is greater on Ivy Bridge or to problems that Intel has with 22nm tri-gate manufacturing process.
According to a post over at Overclockers.com, the first reason is only partly true as although the power density is indeed greater it can't explain a difference of up to 20°C when overclocked Ivy Bridge and Sandy Bridge are compared. Although, there is also a minor possibility that second reason has something to do with it as Ivy Bridge certainly has a lower overclocking potential, but mostly due to heat, as some reviewers were even scared to push it beyond 4.5GHz.
Apparently, Intel decided to use TIM paste between the CPU die and IHS which results in lower heat conductivity or simply the IHS actually becomes a heat barrier rather than the heat spreader. Of course, the TIM paste usage might only be limited to engineering samples sent to reviewers, and Intel is still to give any official details regarding this issue, but for now it is quite possible that this could be Ivy Bridge's main problem, or should we say, its Cougar Point.
As briefly noted by Overclockers.com, the same issue was with Intel's E6xxx and E4xxx CPU lines and probably some others in past. Unfortunately, it looks like all is not well in Ivy Bridge world, and to make things worse we heard a few other things but we'll leave that for another article.
You can check out the Overclockers.com post here and you can check out Intel Ivy Bridge 3570K IHS removal video below.