https://bugs.freedesktop.org/show_bug.cgi?id=52345
--- Comment #6 from Amadeus sha256sum@gmail.com 2012-07-22 21:13:23 PDT --- Very interesting thread. It seams to be the same problem I have.
Regardless of the power settings I never get a higher engine clock than ~75kHz.
[root@amd ~]# cat /sys/kernel/debug/dri/0/radeon_pm_info default engine clock: 200000 kHz current engine clock: 73950 kHz default memory clock: 533000 kHz