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

Gabriel Lavoie glavoie at
Fri Jan 9 16:10:43 PST 2009

2009/1/9 Alexander Motin <mav 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
> dev.cpu.0.freq_levels is just a mix of est and p4tcc levels. By default
> powerd uses all of them. If you really wish, you can disable p4tcc with:
> hint.p4tcc.0.disabled=1
> hint.acpi_throttle.0.disabled=1
> then dev.cpu.0.freq_levels will be equal to dev.est.0.freq_settings.

Working like a charm! I wasn't sure so I added both 0 and 1 for both
cores and it seems to be correct. I had to add them in loader.conf or
device.hints? Put them in loader.conf and it seems to be OK.

>> 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).
> I have just merged updated powerd to 7-STABLE to address this issue.

If I run release, it means it will be available in 7.2?

> --
> Alexander Motin



Gabriel Lavoie
glavoie at

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