Laptop ACPI question

James Snow snow at teardrop.org
Sat May 1 22:22:52 PDT 2004


On Sat, May 01, 2004 at 02:05:36PM -0700, Kevin Oberman wrote:
> 
> Actually, ACPI will greatly improve battery life soon, but not yet. The
> bits and pieces are being fed into CURRENT and I suspect that SpeedStep
> support will be coming soon.
> In the meantime, you can use sysctls to manually adjust CPU performance
> to enhance battery life.
> 
> Look at:
> hw.acpi.cpu.throttle_max: 8
> hw.acpi.cpu.throttle_state: 8
> hw.acpi.cpu.cx_supported: C1/0 C2/1 C3/85
> hw.acpi.cpu.cx_lowest: 0
> hw.acpi.cpu.cx_history: 1453705/0 0/0 0/0

Hmm. In 5.2.1-p5, I don't have anything under hw.acpi.cpu
labeled .throttle*. I do, however, have these:

hw.acpi.cpu.max_speed: 8
hw.acpi.cpu.current_speed: 1
hw.acpi.cpu.performance_speed: 8
hw.acpi.cpu.economy_speed: 1

acpi(4) seems to suggest that these will alter CPU speed,
and presumably battery life as well. Is this not the case?


-Snow



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