Lapping a GPU

1. Yes, depending on the GPU
2. Yes, but I cannot find the link - search around.
3. In the article I read, the guy got 30C lower temps on a 9800gx2 when we got an aftermarket cooled and lapped it and put on some ocz freeze.

However, it is extremely hard to do as you can easily damage the front of the card. Also, you may have to de-solder some parts to give your gpu contact with the sandpaper. It is a seriously hardcore thing to attempt - good luck if you do try it ^_^

The only gpu I've seen lapped is a gtx280 iirc, they have a propper IHS (looks the same as a cpu one). He used it with a lapped HR-03gt and got a drop of around 7~

I think for this you would have to get a different tool.

Think of a cylinder made of aluminum or delrin or whatever. Now the bottom would have to be perfectly flat. Use this in a twisty motion with sandpaper on the bottom and walla your all set. Ofcourse this will take a while.

the gpu is actually pretty flat, if you take it apart and place a razor blade on it you will see that it is no concave like a cpu.

I suggest getting a HR-03 GTX, it will do wonders on the 285. Or wait another week or 2 and the Accelero should be out.