Next up is a Sapphire Radeon HD 4670 graphics card.
The Radeon HD 4670 did not have a "med" power profile, but the default/high state was 750MHz and the low was at 300MHz, which was also the case for the Catalyst driver.
The GPU voltage was unchanged in the lowest power state.
The Radeon HD 4670 on the Radeon open-source driver is not enough to handle Doom 3, but it was more than fast enough when powered by the Catalyst binary driver.
For those interested in more results, there are also some numbers from a Radeon HD 4870, but by looking at all of the results in this article, you should now be able to paint your own picture about the Radeon power management under Linux. The Catalyst driver remains superior for power management under Linux.
If you are after the power consumption comparison between the open and closed-source drivers and other performance metrics, see The Most Comprehensive AMD Radeon Linux Graphics Comparison. There's also some NVIDIA GeForce numbers in A 14-Way Comparison Of NVIDIA vs. Nouveau Drivers.