Enhanced SpeedStep driver available
sobomax at portaone.com
Mon Aug 16 11:08:49 PDT 2004
Colin Percival wrote:
> Thanks to everyone who has been sending me data about their
> processors (and in particular, the 90nm versions), I now have
> a first draft of a Enhanced SpeedStep driver available. For
> people with the appropriate processors (Pentium M only), this
> makes it possible to adjust the cpu frequency via a new sysctl
> (hw.est_curfreq), and have the cpu voltage adjusted at the
> same time.
> I've also put together a very simple control daemon which
> reads kern.cp_time every second and adjusts the cpu frequency
> based on the fraction of cpu time which is idle. This increases
> my laptop's battery life by around 40%.
It would be nice if you can extend it to use whatever speed control
method is available (e.g. ACPI, TCC, ESS etc), so that it can be used on
older machines as well.
> All the code is online at
> Assuming I don't hear any major bug reports in the next few
> days, I'll package these into ports and hopefully get them into
> the ports tree in time for 5.3-RELEASE.
> Colin Percival
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