power consumption (was: xorg +XGI Volari XP5)

Matthew Dillon dillon at apollo.backplane.com
Thu Apr 28 00:29:58 PDT 2005

:>     Not sure what you mean.   The fan controls are automatic.  Cpu
:>     frequency is controlled by ACPI.  It's possible that FreeBSD 5 has
:>     some support in there that we could port beyond the frequency
:>     controls we already have, so the question is... in what way does
:>     FreeBSD 5.x support cool and quiet?
:FreeBSD 6-CURRENT includes the cpufreq(4) framework that supports absolute 
:and relative CPU frequency control, via SpeedStep, Enhanced SpeedStep, 
:PowerNow!, Cool'n Quiet, P4 Thermal Control Circuitry, and a few others I 
:don't recall offhand.  There's also work underway to support a few others 
:like Transmeta's LongRun and whatever VIA's CPUs use.
:There's also the acpi_perf(4) support (merged into cpufreq(4) recently) for 
:ACPI Throttling support, as well as other relative CPU frequency controls.
:The cpufreq(4) framework was MFC'd to RELENG_5, although none of the actual 
:drivers were MFC'd (scheduled for after 5.4).  acpi_perf(4) and 
:kernel-levek P4TCC support is included in RELENG_5 and provides for ACPI 
:throttling and P4TCC throttling.
:CPU frequency is controlled manually via sysctl (and rc.conf), or 
:automatically via the powerd(8) daemon.
:No idea how hard / easy / worthwhile it would be to bring these over to 
:DFly.  Would depend on close the ACPI support is between the two, I'd 
:Freddie Cash, CLCP CNCP            Network Support / Helpdesk

    I took a quick look at the infrastructure and it does look 
    reasonably portable.  I don't have time to port it myself (I have
    too much other work on my list), but if someone wants to have a
    go at it I would be happy to help test.

					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>

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