powerd and increase in energy need

John john at theusgroup.com
Thu Mar 22 07:24:29 UTC 2012


>
>If you are trying to reduce power consumption, why are you limiting Cx
>states to C2 (which save little) and not C3 (which will save a LOT of
>power when the CPU is not heavily loaded).

With my hardware, i5-650, using C3 does not result in lower power consumption
versus C2.  Both states draw exactly the same power.

hw.acpi.cpu.cx_lowest: C3
dev.cpu.0.cx_supported: C1/3 C2/205 C3/245
dev.cpu.0.cx_lowest: C3
dev.cpu.1.cx_supported: C1/3 C2/205 C3/245
dev.cpu.1.cx_lowest: C3
dev.cpu.2.cx_supported: C1/3 C2/205 C3/245
dev.cpu.2.cx_lowest: C3
dev.cpu.3.cx_supported: C1/3 C2/205 C3/245
dev.cpu.3.cx_lowest: C3
71w idle power

hw.acpi.cpu.cx_lowest: C2
dev.cpu.0.cx_supported: C1/3 C2/205 C3/245
dev.cpu.0.cx_lowest: C2
dev.cpu.1.cx_supported: C1/3 C2/205 C3/245
dev.cpu.1.cx_lowest: C2
dev.cpu.2.cx_supported: C1/3 C2/205 C3/245
dev.cpu.2.cx_lowest: C2
dev.cpu.3.cx_supported: C1/3 C2/205 C3/245
dev.cpu.3.cx_lowest: C2
71w idle power

John Theus
TheUs Group
TheUsGroup.com


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