i live in an area where i cant find a sandpaper higher than 1000, i even tried to use a sharpening stone to see if it would yield results. Bad Freaking Idea!
I used to be in a phase where i tried to find cheap alternatives for cleaning scratched cds so i bought a cd cleaner where at that point i though is a $7 wasted, i could buy a balloon! Then i realize that the underneath must be so clear for the cd to be playable, almost mirror finish. I tried that with a copper heatsink from HD2900XT. The difference is big for me as now i can overclock the core at 840 mhz from 820 mhz. Im still finding ways to really clock this thing to the max.
This is the cd scratch removal i bought for $7 CAD at a local radioshack. (i think its a polishing compound, 2000 grit sand paper and a 3000 grit sand paper):
I lapped this heatsink before but i cant get anymore higher than 820mhz:
First phase using the blue 2000 grit paper:
Second phase using the brown 3000 grit then last phase -polished it:
I use OCZ Ultra 5+ thermal paste to cover the gpu as even and as thin as i could:
i tested it right away with amd gpu clock tool after a run of 3dmark06.
i didnt took screenshots before the lapping but i remember its around 65 idle, 80+ under load. im open to any suggestions from anyone