Talk:Power management/HOWTO

Deprecation Warnings

"Warning package sys-power/cpufreqd is deprecated and has been removed from the portage tree". It is always courteous and best to also advise the reader what is now being used as a replacement for cpufreqd! Else, people spend more time finding such trivial information. --Roger (talk) 00:11, 14 January 2015 (UTC)

Theodore Ts'o wrote his explanation on Google+:

* intel_pstate can be disabled at boot-time with kernel arg intel_pstate=disable

* The problem with the ondemand governor is that it doesn't know the specific capabilities of the CPU

* Executing some tasks with higher frequency will consume less power than would a lower frequency taking more time e.g. arithmetic stuff, but not true for all tasks e.g. loading something from memory

* The intel_pstate driver knows the details of the how the CPU works and it does a better job than the generic ACPI solution

* intel_pstate offers only two governors, powersave and performance. Intel claims that the intel_pstate "powersave" is faster than the generic acpi governor with "performance"

The above should be somehow included within the article to accurately describe the default policy for Intel Sandy Bridge and Ivy Bridge CPUs as of kernel 3.9. --Roger (talk) 00:11, 14 January 2015 (UTC)