Hi All,
This just started happening an hour or so ago.
Z77X-UP5TH 3770K not OC, Coolermaster V8, Seasonic 750W modular, 32GB Corsair Vengance,Sandisk SSD, Cooler Master HAF XB case - Mtn Lion 10.8.2
MacPro3,1, no DSDT, on-board video. Temps were running cool @ idle ( < 28°C ). had speedsteps...