Problem on AMD64

Ian Smith smithi at
Mon Dec 22 19:40:53 PST 2008

On Mon, 22 Dec 2008, Dmitry Kolosov wrote:
 > Could you give to us some links about powersaving with EST? For now, i'm using 
 > powerd: 
 > powerd_enable="YES" 
 > powerd_flags="-a maximum -b adaptive -n adaptive -r 30 -i 35" 
 > in my rc.conf. I'm not on AMD64, so i'm sorry, powerd works well to me (125 MHz 
 > on battery and 2.16GHz on AC), BUT battery life time is equal in both cases and 
 > something about 50 minutes, so i think powerd is not so powerfull for me.

     -i percent  Specifies the CPU idle percent level when adaptive mode
                 should begin to degrade performance to save power.  The
                 default is 90% or higher.

     -r percent  Specifies the CPU idle percent level where adaptive mode
                 should consider the CPU running and increase performance.
                 The default is 65% or lower.

I don't think your powerd running and idle percentages are likely to 
work too well; too close together, and too close to the 'busy' end.

Try stopping powerd (/etc/rc.d/powerd stop) then running powerd manually 
in verbose mode in its own console (powerd -v [flags]) to watch how it 
behaves under varying loads.

I suspect that you will find it 'flapping' between some frequencies too 
often at constant load, as there's insufficient hysteresis between the 
idle/running marks.  Compare it with using the default -i and -r and if 
those aren't suitable, try rather smaller variations from the defaults.

If it lacks responsiveness, try decreasing the polling interval.

cheers, Ian

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