Driver Patch Reduces ATI Graphics Power Consumption
ATI graphics cards have become more and more interesting for Linux developers ever since the manufacture released the sources. The latest drive has released power management functions that have previously been neglected on Linux.
AMD developer Alex Deucher released a patch for the free R500 and R600 graphics chip driver to add support for dynamic graphics processor clocking. The "Dynamic Clocks" extension changes the graphics processors clock speed, although functions for modifying the bus and memory clock speeds are still missing for full dynamic power management support like that provided by ATI's "PowerPlay" solution. PowerPlay has not been completely released. And because clock management is often implemented in the form of BIOS calls, the new code will not benefit some users. Despite this, the patch is regarded as a starting point for making the free ATI driver less power hungry.
The current "xf86-video-ati driver" driver is available in the Git tree on FreeDesktop.org. It is most useful to owners of notebooks with the ATI R500/R600 graphics chipset. The code has no effect on desktop machines.
AMD released the specifications for the ATI R500 and R600 in September last year. The release was followed by documentation for further cards and chips this February.