@cadaveca , might I implore a second review of that assertion?
Looking at the mathematics, and assuming a standard atmosphere, the relation between Pressure, Temperature, and Volume is PV=nRT. If we assume that the IHS was solid, the Volume would be constant, which means the pressure would change directly with volume. As the IHS would be sealed during the soldering process, our CPU actually has an internal pressure less than the surrounding atmosphere (250C soldering, 20C atmospheric). If that hole was related to air pressure, it would have to be to return air to the area once the IHS solder cooled. This rather efficiently contradicts what you are saying.
On the other hand, it does reinforce why the mainstream line would have no hole. Researching backwards to SB, there has been no hole on the mainstream IHS offerings by Intel. That kinda kills the theory there, because SB was a soldered chip. You can't make the argument that IB/Haswell weren't soldered, therefore didn't require pressure equalization.
What we are left with is the question as to why there would be a hole on the enthusiast line? The only remaining factors are a much larger TDP, with a slightly larger die area. Because there are more cores, that means those discontinuous pockets of thermal expansion varying rather substantially. This is functionally a situation where thermal expansion varies wildly with location, creating stresses within the IHS that could likely shatter the mechanical bond that the solder forms. In comes a discontinuity to the IHS. That hole can dissipate stresses by changing their concentration and flexing differently based upon the hole's geometry.
So, the counter-argument asks why it's where it is and why is it so small? First off, wikipedia does a decent enough job describing stress concentration:
https://en.wikipedia.org/wiki/Stress_concentration Basically, a very small discontinuity does an excellent job of concentrating stresses. Additionally, the geometry of stresses within the heatsink (largely planar) mean that any one discontinuity will influence the entire surface.
We've established why it just being a pressure release is rather unlikely, without even asking whether it would actually breathe. I mean, the IHS should be covered by both a heatsink surface, and thermal paste. The implication would be that the pressure differential between the CPU air and surrounding air would be enough to actually blow the thermal paste out of the way, right? I'm not sure how this is possible, after you stated clearly that you needed to clean the material out of the holes.
Am I missing something critical here? I've tried to attack the problem as "it's just a pressure equalization hole" before, but the facts don't seem to jibe with that assertion. The thermal loading, as described above, is all I've ever been able to mentally justify. If that's demonstrably incorrect, I'd love to know where my logic jumped the rails.
