Hi there, Does anyone know approx when the each of the 3 fans are supposed kick in? On an iMac Late 2009, 21.5" 4670HD Was in BootCamp, playing GTA IV, and noticed the top of iMac was very hot, and I booted into OS X to check temps, CPU was 45degrees and gfx card was 65degrees (celsius), but you still could not hear the fans, with the fans being around 1000rpm. - Not changed from idle fans speeds. Is this normal behavior? Thanks, any help appreciated.