I have run various cpu intensive tasks in regular mode (built in display, no external) and in clamshell mode. I have noticed that all tasks take 2X-3X longer in clamshell mode. I downloaded intel's power gadget and ran all the tasks again, this time monitoring clock speed, power consumption, and temperature. TESTS in Clamshell Mode: ~1.0GHz, 8W, Temp: ~75c. TESTS used regularly :~2.4 GHz, 35W, Temp: 85-90C The temperatures in clamshell mode never reach any higher than non clamshell temps so there is really not reason for the throttling at all. Sometimes on boot, it is already throttling before I've even gotten things up to operating temperature. Is this acceptable? I'm not even getting anything close to advertised performance here. Hoping to take into genius bar soon but want to go in with a solid case here. I've tried PRAM reset and have also tested this on multiple OS's.