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brucehuynhlee / xnu-speedstep

Automatically exported from code.google.com/p/xnu-speedstep
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Undervolting - where to set voltages? #22

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago 
Hi,

I am using iDeneb v1.4, almost everything is working great!
I remember to have read something about undervolting  or setting voltages.
The sysctl kern.cputhrottle_factoryvolts is read-only, so thats not working.
Is there a way to do that somehow?

My CPU is a PentiumM 1.6Ghz.

PS: Great job! Thanks for your work.

Original issue reported on code.google.com by army.of....@gmail.com on 30 Mar 2009 at 5:26

GoogleCodeExporter commented 8 years ago 
sysctl -w kern.cputhrottle_curvolt=1250

This would set the current voltage to 1.25V.

Somehow I notice the voltage change is not permanent, ie the voltage would 
revert to
the default factory voltage after some time or the frequency step has changed.

I would suggest implementing a proper function for undervolt.
xnu-speedstep also cannot get my CPU freq correct. It truncates the CPU 
multiplier
from 8.5 to 8 and the max frequency of my Core 2 Duo P8400 is 2128 (8X266).

Original comment by drwby...@gmail.com on 22 Jul 2009 at 6:29