Intel Linux Driver Trying Bay Trail Aggressive Downclocking

Intel's Linux open-source crew is toying with aggressive down-clocking for current-generation Bay Trail hardware for greater power-savings and lower heat output.

Chris Wilson of Intel OTC has proposed a patch to be more aggressive about down-clocking -- dropping the Atom/Celeron SoCs to their lower frequency/power states more quickly after being in a ramped-up state. Assuming the workload has finished, this should yield a quicker return to the lowest power state for maximum power-savings / longest battery life and lower heat output.

Chris explained with the DRM driver patch, "Baytrail uses the RPS wait-boosting mechanism of Sandybridge+ but also has a very lax downclocking strategy (upclock if more than 90% busy over 76ms, downclock if less than 70% busy over 450ms). This causes Baytrail to use maximum clocks, and for them to stay high, when doing simple tasks such as scrolling through webpages. However, we can take a leaf out of the same wait-boost mechansim and apply the aggressive downclocking strategy from Sandybridge+ as well."

Of course, if the driver down-clocking is too aggressive, this could cause performance issues, which is now being discussed in the aforelinked driver thread. Hopefully the results will pan out (and we will test it ourselves once merged) and hopefully this will provide Bay Trail Linux users with some benefits.