https://bugs.freedesktop.org/show_bug.cgi?id=38917
--- Comment #2 from Alex Deucher agd5f@yahoo.com 2011-07-05 06:40:11 PDT --- There's no infrastructure in place yet to automatically lower clocks if the temperature gets to a critical level so we limit the clocks to the boot up levels for now. On most systems the boot clocks are much closer to the performance clocks.