I planned on lapping my heatsink, but before i do need to know if i really need to. How can i gauge whether a heatsink is truly uniform and flat as they say. Are there any techniques that i could do in order to test this? Thanks
When I lapped my TC-4 on a piece of glass with 800 grit sandpaper, I could clearly see that the center of the surface of the waterblock was concave. No marker was needed. The lapped part stood out from the unlapped part.
Put some thermal compound on your heatsink. Attach it on the processor firmly.
Then take it off and look at the place where the processor touched the heatsink. If all the compound squeezed out the sides so that you can see the bottom of the heatsink without any patches of compound in the way, then your contact isn't too bad.