I have heard of other intel cpu having a hardcoded lowest voltage. Mine is a duo T2500 and it has the same hardcode, mine at .95v. Since my cpu works at .95v for the next available higher frequency, I thought to just set the base frequency from the default lowest of 1,000,000 to 1,333,000 in that it aught to use the same power but yield a higher performance gain. So far so good.

Here is what I did to /etc/rc.local to set it for boot..


# By default this script does nothing.

echo 1333000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
echo 1333000 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_min_freq

exit 0

Heya. Great "hack".


But if you want to save even the latest microampere of power this solution is not the best.
With PHC you reduce the voltage the CPU gets, but you can not reduce the current (amperes) the CPU takes. And it takes more current the higher the frequency is.

How much the difference is one need to test on its own machine.

I am sure there is a trade off somewhat.

Doesn't the current really only significantly increase when there are actual calculations performed as opposed to just the clock ticking faster?

I am not sure how much effective this is. Maybe you can get some results from powertop?

Interesting, I was already thinking about overclocking to avoid wasting voltage at the lower frequency, but I will have to check the delta power consumption when the cpu is idle.