Speed Steping hw.acpi.cpu.cx_support

Bruno Ducrot ducrot at poupinou.org
Mon Sep 26 06:31:52 PDT 2005


On Sun, Sep 25, 2005 at 07:49:08PM -0700, Kevin Oberman wrote:
> > Does any one know how to config speed steping.
> >  
> > sysctl output > hw.acpi.cpu.cx_support:
> >  C1/1 C2/1 C3/85
> >  hw.acpi.cpu.cx_support C1
> >  hw.acpi.cpu.cx_support 100.00% 0.00% 0.00%
> 
> Add th line:
> performance_cx_lowest="LOW"
> to /etc/rc.local. To get C3, you must run without USB drivers and, with the numbers you quoted, C2 is not going to buy you much.

Except that Cx stuff have absolutely nothing to do with
speed steping.  The Cx states are some power states
entered by the processor in the idle loop.  The higher
is less power hungry at the cost of more latency to
leave this power state.

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.


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