What is the name/part nr. of the battery?

I think I know the problem. In iStat the GPU Die sensor is not showing any temperature . So I put the fans on max, blowing loudly and ran a game. Smooth all the way. So I guess the new GPU 's temp is not being monitored so therefor runs hot, with the fans running low.

My tip: Use an app to control your fans speed before playing. Good luck!

Same problem here.. upgraded my 27" late 2009 with a 6970M 1024 MB. Works ok, but games performing worst :/

Opened it up, checked all the cable's.. nothing. Not a clue.