EST (Enhanced Intel SpeedStep(R) Technology) on amd64

Gabriel Lavoie glavoie at
Fri Jan 9 22:31:51 UTC 2009

This is what I did by setting freq_lowest to 1200 but it would also be
nice if we could configure the steps, or at least, be able to
configure more powerd. Some setting like going from lowest frequency
to highest frequency in one step if load is over 10% without having to
wait a few msec for every steps between would be useful.


2009/1/9 Nate Lawson <nate at>:
> Gabriel Lavoie wrote:
>> Another question. Any reason why powerd doesn't use
>> dev.est.0.freq_settings when it is available instead of
>> dev.cpu.0.freq_levels?
>> On my system:
>> dev.cpu.0.freq_levels: 2500/88000 2187/77000 2000/47608 1750/41657
>> 1600/44616 1400/39039 1200/41800 1050/36575 900/31350 750/26125
>> 600/20900 450/15675 300/10450 150/5225
>> dev.est.0.freq_settings: 2500/88000 2000/47608 1600/44616 1200/41800
>> If I don't lower the polling time of powerd to 100ms, my system
>> becomes way too much unresponsive because powerd takes too much time
>> to increase the frequency, step by step and there are a lot of
>> settings with dev.est.0.freq_settings (14). With
>> dev.est.0.freq_settings, the minimal setting is high enough so the
>> system stays responsive and powerd would bring it up to max frequency
>> quickly enough, even if the polling time is still kept at 500ms. This
>> would work more like Windows or Linux where the lowest frequency at
>> which the CPU will drop is the lowest EIST gives (here 1200 MHz).
> levels is derived from settings. Set a lower bound with the sysctl for
> freq_lowest.
> --
> Nate

Gabriel Lavoie
glavoie at

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