Voltage Tweaking Comes To R600+ GPUs On Linux

Earlier this month we reported on vastly improved ATI power management support within the open-source Radeon graphics driver stack for Linux that now supports dynamic power management along with different power management profiles. Following that we provided a detailed look at the ATI Linux power management support with plenty of charts showing how the power management is working out with this latest open-source code.

While the latest power management patches are great for adjusting the GPU frequencies to conserve energy, now those with Radeon R600/700 hardware (ATI Radeon HD 2000/3000/4000 GPUs) can benefit from voltage adjustment support too. R100-R500 ASICs already have voltage adjustment pretty much implemented within the open-source code, but AMD's Alex Deucher has today provided support for the newer ATI Radeon generations.

The power management voltage support comes by means of four patches:

- patch default power state with default clocks/voltages on r6xx+
- radeon_set_power_state fixes
- voltage fixes
- add support for SetVoltage cmd table

Right now these are just patches sitting on the DRI mailing list. These patches potentially could still end up in the Linux 2.6.35 kernel otherwise they will make it in the Linux 2.6.36 kernel a few months later.