I have done a few experiment on why some games like team fortress 2 keep dipping in fps.. I was convinced it was a CPU bound issue but after a few hours of investigating the issue, I ran Furmark and prime 95 together. CPU quickly from 2.2 ghz throttle down to 800 mhz and alot of 3d app does the same thing from (2.2 ghz to 1.x ghz) then when I close furmark then it instantly goes back to 1.9 ghz See screen shot for proof Please tweet this, reddit this, Facebook this, Make Apple aware of this issue! http://i.imgur.com/fzUfa.jpg http://i.imgur.com/64eOc.png EDIT: I tested it, it is not heat related! It the power requirement, I Turned off Wifi and disabled the LCD Monitor & plugged in external lcd . I am using the same program and same tool like the last one. http://i.imgur.com/etls3.jpg TL;DR: Any GPU usage will cause throttle on the CPU because insufficient power requirement?