Sep 29, 2009
I also use the ultra 120! As for lapping, its a very opinionated topic many people have different views ! heres my opinion ! The ultra 120 had a pretty good dip in the middle that i felt would have caused a gap unless the chip was raised in the middle in wich case not so much, some people say that they are both made so that the chip is raised and the heatsink has a dip but, Some people also say to use turtle wax to give your heatsink that mirror finish~ "dont" The fact is that mass produced products create the need to focus more on quantity then quality so the heatsinks are not as perfectly flat as you would expect! So lap away i say! be aware that your copper will be more prone to corrosion without the nickle plate over the top but a good ractice is to reseat your heatsink periodicly and clean and replace the thermal paste so yopu may be able to mitigate this. the bare copper surface should be a better surface for thermal transfer and with a good lap your gonna have a much flatter surface creating a better bond between the heatsink and cpu . Tips use auto sand paper start with a 400 roughly and move to a a600 / 800 1000 up to a 1500 or even 1600 at the end your "mirror" finish will reveal itself wth only mild scratching visible i tell you to start with a gritty grain because the first few passes are just straight work to get the first few layers peeled back! take your time slowly on a flat surface just use it dry and make shure you use a air blast and some 99% alchohol to clean her up after! use a lon razor blade and drop it flat against the surface it will reveal the trueness of the the surface GOOD LUCK !
I lapped both the Ultra 120 cpu heatsink and the cpu. I didn't have to because I was already getting excellent cooling results with the Coolermaster HAF 932 case. I just did it to see if an old fart like me could do it and I wanted to see what happens. Temps dropped a couple of degrees after lapping.

I cannot say that lapping was the direct cause of the temperature drop because I replaced the stock thermal compound with IC Diamond 7 Carat Thermal Compound. The temperature drop may have been a combination of both.

For the typical user lapping is not necessary. A difference of 3 or 4 degrees will not matter. It may help a hardcore gamer into serious overclocking and mutiple video cards on a suicide mission to save the planet from alien invaders.