the true disapointment with haswell is the lack of significant improvement with delidding. While, like IB you can see a solid 10C drop in temps, haswell has a far more agressive heat profile then IB. With minimal bumps in voltage resulting in massive jumps in heat, meaning even with a delidding you could see very little improvement in your overclock, as the chip will still rapidly produce massive ammounts of heat, very fast.
While i understand Intel has their own formula for determaning TDP for their chips, i've said it before, by moving the VRM onto the chip, they invalidated their calculation. The Haswell performs and benches like a much hotter chip then it's advertised TDP. The first warning to benchers this was the case, was when benchers were getting thermal throttling from turbo mode on the stock intel heatsink, and then those same benchers hitting the thermal ceiling with a very small voltage bump and moderate overclock (4.2) with a solid air cooler the hyper evo. People can overclock 125W amd chips pretty aggressively with a lot of vcore on a hyper evo... meanwhile they were thermal throttling with a very modest bump in vcore on a tiny overclock.
This raises a question about the formula intel used to calculate the TDP of their haswell chip, as cpu coolers rated for far higher tdps were struggling with haswell. This article is a bit of an eye opener, as most of those cpu coolers are not jokes. The noctua isn't all that different from the old cpu cooler i used to use to keep my PhII x4 965be cooled. It managed to keep a PhII at a 3.7ghz overclock in a 35C room under 55C while running prime. So that's no joke of a cpu cooler. That it struggles so badly with haswell says something significant to me.
Simply put, you need a water system with a serious rad/fan combo to make a serious stab at a haswell overclock. Air isn't enough anymore.
Dinko Mat :
What about to improve the thermal performance of Haswell by removing Integrated Heat Spreader Removal and Replacing IHS Thermal Paste. You can get 10 or more degree C less temperature.
yes... it will give you 10+C better temps. the problem is haswell basically heats up exponentially with more voltage. So this rarely gives you a lot more overclock headroom then you had pre-delidding. Ignoring those NO2 guys or the ones using some peltier or other exotic cooling solution, Haswell doesn't really benefit as much as IB does with delidding. another 0.1ghz or 0.2... at best. and that might be a bit optimistic. The real trick with haswell is getting the right batch... apparently some of the chips from certain asian foundries are atrocious overclockers with almost crippling heat problems...