Intel Intelligent Power Sharing Coming To Linux

Jesse Barnes, one of the Intel developers responsible for working on their Linux graphics driver stack, has published a new patch that adds "dynamic performance control support for Ironlake." Ironlake was Intel's codename for the onboard GPU found on new Clarkdale / Arrandale processors like the recently reviewed Intel Core i3 530. This patch takes advantage of a hardware performance and power management feature to actually increase the GPU clock (or to "overclock" it in a Graphics Turbo mode) when needed to deliver better performance. This patch is fairly large and can be found currently on the Intel driver mailing list.

One item not provided by this patch that we would really love to see -- and will just become more important with these clocking improvements -- would be exporting the clock and voltage information to a sysfs interface.

This patch is also a prerequisite for Intelligent Power Sharing (IPS), which is another hardware feature found on the new Core i3/i5 Clarkdale/Arrandale processors. Intel's Intelligent Power Sharing is described as "a driver-based power management mechanism that provides intelligent power sharing across cores. With these capabilities, performance for the processor and graphics processor can be scaled up or down, depending on system activity and thermal tolerances. The result: stellar performance and prudent power use."

No Intelligent Power Sharing patch has yet to be published for the Intel Linux driver, but it's being worked on and is expected to arrive soon. Jesse Barnes confirmed this in a new blog post where he also shares this new work is increasing the graphics performance by about 15%.

In Jesse's blog post he also comments on the new DRI2 swap events (Mutter/Clutter Work Leads To New GLX Extension) and other sync and swap improvements.