CPU Heatsink contact surface

[mjscott22]

I just bought the arctic-cooling silencer 64TC for my 3200 processor. There is a machine polish on the back of the heat sink where it contacts the processor, but there are little grooves all over where I think it should be smooth like the stock heatsink. I also had this problem with the arctic cooler for my 9800 pro, but i sanded that one with normal fine grit sandpaper to make a smother more of a mirror surface. Just wondering if I should try to sand/polish my CPU heatsink or let it go. I dont really think it could make good contact with the back of the processor the way it is. Im also using Arctic Silver 5.

Thanks guys

[Ginsu543]

If the grooves are large enough for you to see clearly with your naked eye, I'd sand it down, being careful to make a very flat surface. Otherwise, those grooves will trap air, which will prevent smooth transfer of heat from your cpu core into the heatsink itself. Of course, the purpose of putting thermal paste in between is to fill in those grooves with heat transfering material, but smaller the grooves the better.

[Colin]

Hey mjscott22. As Ginsu543 suggested if the grooves are big, you might want to lap that sucker. It's not necessary to get a mirror finish, you want it as flat as possible.

[mjscott22]

thats what im thinkin. I read somewhere that you are supposed to sand down to a 10micron grit sandpaper, but just recently read 600 -> 2000 should be good. Thanks for the info

[Ginsu543]

Tell us how it works out.

[mjscott22]

Well it turns out all I had was 2000 grit sandpaper, so I wet sanded it for about half an hour. the edges were starting to get very smooth and shiny, but there were still some grooves in the middle section, but I got tired and just wanted to put my computer together so I cleaned it up and slapped some AS5 and put it together. It worked though, and turned out a LOT better than it was, you just be ready to spend some time on it.

[Ginsu543]

Great job!