Originally Posted by The Hundred Gunner
Removing my IHS raised my temps about 3C, but i think that's because my HS clips on (you can still jiggle it or twist it a little when it's clipped in). I'd say remove the IHS if you have a HS that screws in or solidly clamps onto a bracket.
I lapped my IHS, though, and it gave me good results, about 3C drop. Plus, since i had removed my IHS i got to replace the crap that they had in between for stock (they missed like half of the damn core). The IHS was also very concave, as was the stock HSF (took me about 3 hours to get it flat).
It is exactly as you have surmised. That can be solved by grinding down the retaining bracket mounts, preferably when not mounted on the MoBo. Perhaps you already have that on your "To Do" list...
Dockery, if you don't mind removing and re-seating your HSF multiple times, consider just lapping the HSF and see what kind of results you get. If you're not satisfied then Lap the Core... and then remove the IHS if you still are not happy. Just remember, Thermal transfer is based on the following:
1) Mass to absorb thermal output.
2) Airflow to remove the thermal output from the mass
3) Efficient thermal transfer accross mated surfaces.
4) The "flatness" of the surfaces.