Now here's some overall power consumption and GPU core temperature graphs generated by the Phoronix Test Suite for the previously shown individual tests plus several other OpenGL tests (more GpuTest cases, etc).
For the averages throughout all of the OpenGL stress tests, plus idling in between tests, the Radeon HD 6870 on the open-source Linux graphics driver with R600 Gallium3D driver had an average core temperature of 59.7 degrees. When enabling Radeon Dynamic Power Management, the average core temperature for this high-end graphics card during the same workloads and idling periods was 54.5 degrees -- a drop of over five degrees Celsius. The Radeon HD 6770 temperature went from 46.1 to 44.0 degrees and the Radeon HD 4890 went from 70.1 degrees to 69.0 degrees on average.
The average system power consumption was also shown overall by the Phoronix Test Suite. During all of this testing, the Radeon HD 6870 by default had an average power consumption of 169 Watts but it dropped to 130.6 by simply setting radeon.dpm=1. The Radeon HD 6770 graphics card went from consuming 117.5 Watts on average to now at 107.0 Watts. The Radeon HD 4890 graphics card went from 179.6 to 166.5 Watts.
Overall, the Radeon Dynamic Power Management support found within the Linux 3.11 kernel is very promising. Being mid-way through the Linux 3.11 development cycle, AMD believes most major bugs with this DPM code should be worked out. The support will still be disabled by default for Linux 3.11 and not turned on "out of the box" until a later Linux kernel release, but comfortable Linux enthusiasts can easily setup Radeon DPM. For modern Radeon graphics cards, the benefits of Radeon Dynamic Power Management are very noticeable with decreased power consumption and lower temperatures, as clearly shown by today's benchmarks. For other hardware, DPM means dramatic performance improvements.