CPU & heatsink lapping has anyone done it?

http://www.tomshardware.com/forum/252942-29-some-notes-...

I did it. Dropped my temps quite a bit. Takes a fair bit of time tho. You'll need 600, 800, and 1000 grit sandpaper. 1200 as well if you want a real smooth finish.

Just be careful, if you can wear some latex gloves that's a good idea. If not, it's ok just try your best to not touch the pads under the CPU. Cleaning with alcohol and non-particulate wipes. Make sure as you do the lapping, you rotate your grip on the CPU every minute or two so that you don't get uneven wear.

Just so you know, if you don't already, it will void your warranties due to "hardware alteration"

And yes you can lap a heatsink too although they're generally very well done and won't give much improvement. I did mine, sanded off a nickel layer, and then a thin copper layer, and then there was more nickel under that lol. Kinda stupid really, nickel doesn't transfer heat nearly as well as copper... but that was my bad for getting the cooler I did. Shoulda done my homework hah.

If your cooler has good contact already, I wouldn't recommend doing it. I had a really wonky CPU so the contact was ***, literally a strip down the middle and temps were like 85C in Prime95. I guess what I shoulda done was brought the CPU in for a replacement, but I just lapped it and fixed it all myself, brought temps down to like 55C until I overclocked.

I dropped my temps from 5 to 8 degs C - here is what I did:

1. Did nothing to the CPU heat spreader. Because this heat spreader is a thin shallow drawn sheet metal part, and the expansion characteristics can be determined only by lab trials.

2. Did some polishing (some call it lapping) to the base of the heatsink, CM V8 in this case. The base is thick enough to be rigid during the heat transfer in operation. The purpose of the polishing is to make the base flat (or flatter), not to obtain a mirror finish which will do nothing in itself. Flatness is the key, not mirror finish.

Re-assembled everything. Temps dropped from 5 to 8 degs.