I just recently bought an imac computer and my two friends who know a lot about apple computers thought that the fans and temperature might be a little high. The cpu fan at idle runs at just under 1200 rpm's, the harddrive fan runs at 1100 rpm's and the optical drive fan runs at 1000 rpm's. The temperature itself 40-44°c. The other imac that they know of is a year old, so we weren't sure if there were newer upgrades that might be making the difference between our speeds and temperature compared to that one.