CoolerMaster Hyper 6

CoolerMaster Musketeer2

CoolerMaster Musketeer

Corsair TwinX512-4000

Enermax CS-5190AL-061


Lapping Your Heatsink
Article by Anion, 23 March 2003


Overclockers usually tend to try and squeeze the most juice out of their system, pushing it to the limit. One very common result of this is that the heat level rises. To cool the system we use a well ventilated case, fans with the best airflow, the best CPU cooler we can afford and even watercooling systems. What if you can't afford buying the best and the greatest cooling systems? For one thing, you can lap your heatsinks or waterblocks, which usually leads to some decrease in temperature. All you'd need to buy is some sandpaper.

Why do lapping at all? Due to the machining process the heatsink's go through, the CPU contact area isn't exactly smooth. To our naked eye, the heatsink's base seems flat and smooth but it has microscopic grooves all over. These grooves and gaps in the base cause a less than optimum contact area between the heatsink and the CPU core. Even though the gaps are filled with thermal paste, heat transfer is less efficient than if there was direct contact.

Here's a short and quick guide to lapping your heatsink. All the equipment you need is some sandpaper of various grit, i.e. 400, 600, 1000, 1500 and 2000.


You will need to start sanding the base of the heatsink with 400 grit sandpaper. The higher the sandpaper grit, the finer the sandpapering will be, and as a result, the smoother the sanded surface will be. Place the heatsink somewhere flat, preferably on top of a mirror or piece of glass. Start sanding using the 400 grit sandpaper on any direction. Change to a higher grit sandpaper when you feel you have sanded enough on the previous grit. Repeat using higher and higher grit sandpaper i.e. 400 grit , 600 grit , 1000 grit , 1500 grit and lastly 2000 grit.

(Ed: For an easier sanding process, wet the sandpaper using some soap and water. The mirror shine is obtained by using some Brasso to polish the lapped surface, though some don't recommend polishing with metal polisher as this might impede performance. Anion *did* use some Brasso though, so this particular step can be considered optional.)




My test system:

  • P4 1.6A Ghz
  • MSI 645 Ultra / SiS 645
  • 2x 256MB Apacer PC2700 DDR RAM
  • 80GB Western Digital 8MB 7200rpm
  • 20GB Maxtor 5200rpm
  • 64MB GeForce4 Ti4200

Room temperature was 31C.

Here are the results!


A 2C drop in load temperatures, pretty good results don't you think? Happy lapping!

Thanks for reading this review, and I hope you'll check back for more in the future. Comments and questions are most welcome. You can discuss this article in our forums.


All original content is © 2001-2003 8Balls Hardware- All Rights Reserved. Other Names, titles, and images are © material of their respective owners.
View our Privacy Policy / Terms of Use.