Okay, so I downloaded Fan Control: Current Temperature: 100*F Base Speed: 1000 RPM Lower Threshold: 104*F Upper Threshold: 160*F Current values: Left Fan: 1774 RPM and Right Fan: 1765 RPM. But when I run iMovie / virtual world games the fan speeds up to 2600 to 2800 RPM. Is that normal? There's this low whirring noise by the apple sign. Anyone think I might have a fan problem? it's not a loud whirring. If I have music on, or tv on, you can't hear it unless it's dead quiet in my room. I have an iMac 24" aluminum.