The search for higher frequencies hasn't lost intensity, and the eternal battle against temperature is harder than ever. As we add more cores to our chips, cooling becomes a central topic, but some enthusiasts and overclocking professionals go to extreme lengths by combining “delidding” with “lapping”. In other words, they mechanically remove the integrated heat spreader from processors... and then sand them down.
The world changed for many users when they discovered they could take their old Pentium, flip a couple of jumpers on the motherboard, and force them to run at 75 MHz. The first Celeron chips (loved and hated equally) jumped from 300 to 450 MHz almost effortlessly. And even today, on systems with dozens of cores per processor, we try to “steal” some extra MHz. However... temperature is a limit we must face sooner or later.
Replacing the cooler with a bigger one, optimizing airflow in the case, and adopting liquid cooling solutions are steps in the right direction. In our basic guide to undervolting and underclocking we also explore the concept of delidding, which separates the processor from its integrated heat spreader. This is especially useful for older Intel chips, and in extreme cases can reduce their temperature 20 degrees or more. But the story doesn't end there: In addition to delidding, some enthusiasts and overclocking professionals decide to add lapping to the equation:
On their latest processors, Intel managed to reduce the thickness of the “die” (the chip's main contact point) to lower overall temperature. In relaxed terms, lapping is nothing more than surface correction. The fewer defects, the better the contact between different materials, and consequently, heat dissipation. Now, working with metals isn't particularly risky, but lapping silicon requires special tools... and a pair of steel balls.
With all the classic “cringe” that characterizes LinusTechTips, and the destruction of a processor during the experiment... the method works. How much did the temperature improve? Between 3 and 4 degrees, but without more solid validation it's impossible to determine if the improvement is a product of lapping, or of the new liquid metal between the processor and its cooler. A more “correct” way to proceed was shared by der8auer a couple of months ago, and I definitely recommend following his instructions closely. In summary: Sanding the processor is truly crazy, but for a professional overclocker, those three degrees could make a huge difference...
