I've had my iMac for two years now. I play a lot of games and watch a lot of HD videos. In the past week, the computer has gotten a lot hotter than usual and it stutters a lot, and I feel like the two are related.
Today while playing a game I noticed that the GPU Diode reached 70 C (using iStat Pro), which I have never seen before. Therefore, the CPU fan was at 2400 rpm.
I play a lot of games, including this same one, and I have never seen the GPU this hot before, and almost never hear the fans running so loudly and so rapidly. (I can't even recall a time when I could very clearly hear the fans running.)
Could all this be a sign to a more bigger problem?