Recently bought a 2011 iMac 27", it's a top end model with i7 3.4GHz CPU, AMD 6970M 2GB, 16GB. I went with an SSD only (no hard drive). I think it might be overheating. Whenever I play Crysis, after a while the game's frame rate will slow right down to sub 5fps levels, then back up again to 30fps+, and it will do this at regular intervals (about every 10 seconds). I've also noticed this happening during a 3D Mark 2006 benchmark run. I read somewhere that this could be due to the GPU overheating, where the GPU will rapidly downclock itself to a very low MHz, then back up again once its cooled down a bit. Some observations: This happens when the room is quite warm, I'm in quite a small room and gets hot when the iMac has been running for a while (also had this problem with a dual GPU PC). It takes a while for the slowing down/speeding up to kick in, probably after room has warmed up. The problem is alleviated if I open a window/door to let the room cool down. The problem is alleviated if I fix Crysis' frame rate to 30fps. Is this a known issue with the iMac? Will I just have to put up with overheating when it's under stress (playing games etc.), finding ways to keep it cool? Is the top end iMac's hardware is at the absolute limit of what the cooling system can cope with? On the plus, I am impressed with the performance, I have Crysis running at 2560x1440 +2xAA and with everything on High or Very High.