I'm using a Mac Pro mid 2010 5,1. I have Boost A, Boost B & Intake all set at heatsink 50C/75C. Ambient is 37C. CPU A is about 54C at idle. In this state Boost A is at 800, B at 800, Intake at 600 & Exhaust at 950. When I put full load on the processors, the temps quickly rise. The fans don't spin up until CPU A is about 87C - 1 min 50 sec after full load was applied. Once the fans spin up, CPU A drops to 72-73C. After about 4 minutes, the fans spin down. CPU A then rises to 82-83C and holds. In this state Boost A is at 1700, B at 1500, Intake at 1150 & Exhaust at 1430.