I got my 6800 GS AGP, and am very happy with it. I have read that it is possible to unlock the extra pixel shader and 4 pipes using Rivatuner, but if you see artifacts, that I should just turn them back off.
My question is this: I'm very pleased with this card's performance (Oblivion works so well!). If I unlock these things, and don't immediately notice artifacts in the game, but they turn out to be damaged, can that do anything bad to the card? I know you want to turn them off if you see artifacts since that would be distracting. I just don't want to do something that might end up permanently damaging something if I don't happen to be observant enough.