U7300 - no reaction to undervold?

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Joined: Sat 12. Feb 2011, 15:29

U7300 - no reaction to undervold?

Post by pheidrias » Sat 12. Feb 2011, 15:44

Hi folks!

I'm running an ubuntu system (10.10 Maverick Meerkat) and installed pch accordingly to http://openmindedbrain.info/26/10/2010/ ... -maverick/.

Unfortunately I have the impression, that die CPU doesn't react to the undervoltage!
I can set all frequencies to 0 via

Code: Select all

echo "0 0 0" > /sys/devices/system/cpu/cpu0/cpufreq/phc_vids
echo "0 0 0" > /sys/devices/system/cpu/cpu1/cpufreq/phc_vids
or via phc tool and system won't change or crash :-(.

Is it possible, that phc doesn't work with the intel u7300-processors?

Kernel: 2.6.35-25-generic-pae-phc

thanks a lot for help,

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Joined: Wed 30. Mar 2011, 17:41

Re: U7300 - no reaction to undervold?

Post by sanbeiyan » Wed 30. Mar 2011, 17:52

Are you talking about su2300 ?

I tested for a whole day, it seems that the reported VID from PHC and readmsr is not correct,
which are 26, 15,13 ==> 26x16+700 , 26x17+700, 13x15+700 ==> 1.16V, 0.972V and 0.895V.
However, the figure from cpuz and rmclock is between 0.975v and 0.875v.

When the cpu is idle, the core temp is the same no matter you set a "26" or "13" to vid. However, when the CPU is at full load @1.3GHz (2x burnMMX), a "26" give the core temp of 50deg while a "13" give the core temp 45 deg. "17" give a temp of 46.5deg. This indicate that the VID from PHC is working.

But in Win, when cpu @ 1.3GHz at full, it is running at ~ 0.975V.

Thus, seems the real benefit at full is undervolt from "17" to "13", actual benefit is less than 2deg.

A bit disappointed.

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Re: U7300 - no reaction to undervold?

Post by Docet » Wed 30. Mar 2011, 22:12

Folks if you want a readable VID and a tester to see the actual voltage take a look at phctool:

http://linuxsolver.blogspot.com/2011/02 ... buntu.html

In case of SUxxxx and Uxxxx processors remember they are "Super Undervolted" and "Undervolted" versions, so they are surely cool and 2 degrees of gain is still something. Be sure that other CPUs can gain much more results.

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Joined: Mon 23. May 2011, 07:34

Re: U7300 - no reaction to undervold?

Post by tarapozan » Mon 23. May 2011, 07:37

If now use your own bios )

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