[Debian-eeepc-devel] saving battery

[Trent W. Buck]

Robert Epprecht <epprecht at solnet.ch> writes:
> I don't know what's the difference between using cpufrequtils and the S.H.E.

CPU frequency scaling (called "P-states" by ACPI) is a widespread
technology.  By loading a driver (e.g. acpi-cpufreq) and a governor
(e.g. ondemand, performance), the kernel can manage CPUs' P-states.

Last time I looked, the userspace utilities like cpufrequtils, powernowd
and laptop-mode just provide a way to change governor when you
(dis)connect AC.  IMO they're useless as at Squeeze; the default
governor (ondemand) is a reasonable choice for both battery and AC: it
chooses the P-state that best meets the current system load.

S.H.E. is an Asus-specific technology for under/overclock (of the FSB?).
It is orthogonal to P-states, and is managed by eeepc-acpi-scripts using
the eeepc-laptop driver.  AFAIK, other packages ignore S.H.E. entirely.