Intel's fourth generation of Core processors, also known as Haswell, are much more efficient in terms of performance per watt. Like the predecessor Ivy Bridge, they do still get very hot when you overclock them. There is something you can do to prevent that, but it's a risky endeavour. This guide shows you the best and safest way to do it.
Haswell is of course an improvement over the previous generation. Better performance per cycle, a significantly faster IGP and support for 4K monitors. Good news for overclockers are the much higher memory clock frequencies that are possible. However, the new CPUs also get a lot hotter when overclocking.
A big reason for this is that, like Ivy Bridge, Haswell has Intel's 22nm ‘Tri-Gate’ transistors. These are significantly smaller than the 32nm transistors from Sandy Bridge. Ivy Bridge and Haswell processors use less power, but the components are located closer together which causes more heat production.
Another reason for the increased heat is that Intel uses different cooling paste between the CPU and the heatspreader underneath. It's unclear exactly why they changed, but it likely has to do with cost or production tempo. Either way, the new cooling paste doesn't work as well.
Replacing the cooling paste is a process called delidding, when you remove the CPU and put it back again with new paste. It's also possible to remove the heatspreader in case of liquid cooling. EK has special kits for this, where you end up connecting the liquid cooling system directly to the processor without the socket lid in between. The approach we take in this guide keeps the heatspreader.
Delidding can have a very beneficial effect on the temperatures, up to 20 degrees can be achieved under full load when you use liquid cooling. With air cooling it gets up to 10 degrees cooler. Better cooling of course means more overclocking potential.