installed the the latest 2013-06-29-saucy build and enabled radeon.dpm=1 in grub.
loving it, full speed desktop and low fan noise, i've lost vmware support (can't compile all the modules) but worth it.
using a HD6970 on my desktop, doesn't seem to work on my e350 APU mini-itx machine though i get a black screen.
Code:
lee@kubuntu:~$ dmesg |grep dpm
[ 1.532151] [drm] radeon: dpm initialized
AMD Has Massive Radeon Patch Set - Power Management!