I want to you to underclock the card cpu core clock to 900mhz.
Reason being for a oc ati card to be clipping like that in games that you mentioned its probably related to that and get abit too hot.
As for the games itself check the settings and keep them on medium high or medium.
If you don't need alot of graphic detail in game, like bright sparly scenary or glittery space scenes crap, flesh wounds, gunshot marks or whatever.
It would be best that the game doesn't need alot of resources from your gpu causing it to short out unexpectedly or epically die one day.
Afterburner 3.0.0 Download
Test it at 900mhz first and see how it does, if seems good keep that way.
If you want more speed, I recommend you slowly bump up the speed and test a game or 2.
When you find that Uh-oh my card is doing the clippy problem again, clock it back to the speed where it was perfectly stable and be done with it.
For the card I hear its a beast and a good one at that, but that beast maybe headed to er room at gigabyte hq eventually.
I recommend you look into nvidia gtx 700 series card in the future.