Atomic guide to CPU lapping

We give you the low-down on how to get your CPU and heatsink flatter - and running cooler - by lapping it to within an inch of its silicon life!

In the mad enthusiast rush to squeeze more clocks and speed out of our gear, there are a few hurdles along the way that hold us back, one of the largest being heat. Heatsinks draw it away from the CPU, and radiate it, but it is in this step that they sometimes fall down.

Assuming ours is a perfect world, every heatsink would have a perfectly flat base, and every Integrated Heat Spreader (IHS) on a CPU would also be flat, needing only a smidgeon of thermal goop to provide the material needed for the very small gaps between them. Sadly, our assumption was a little misguided, and neither of those things exist.

The IHS on a CPU is nearly always extremely convex (raised in the middle, and falling off towards the outer edges), and is made of copper coated with nickel. We’ve chosen the Core i7 920 chip (mostly because we’re crazy, and have no respect for misbehaving tech) and a
Thermalright Ultra 120 Extreme 1366 cooler for this experiment, and we’ll show you not only how to get great results for little money, but what we managed to achieve.

Running our CPU at idle, we recorded the following temps at idle, and at load under OCCT after a period of twenty minutes:

Core i7 920 - Idle

Core i7 920 - Load

Click on to see just what we do to it...