Undervolting CPU with ubuntu 16.04

Question

I was looking into undervolting my laptop CPU. I could only find guides on phc that are said to be outdated. Is there a tool for that in the new version? Is it possible with TLP?

Solution

Yes, with TLP you can scale you CPU frequency (Look at this post: TLP don't change CPU frequency). You can specify to reduce the CPU frequency.

CPU_SCALING_GOVERNOR_ON_AC=powersave
CPU_SCALING_GOVERNOR_ON_BAT=powersave 

More info here: http://linrunner.de/en/tlp/docs/tlp-configuration.html

However I found another article about CPU limiting

http://blog.scoutapp.com/articles/2014/11/04/restricting-process-cpu-usage-using-nice-cpulimit-and-cgroups

Although, it isn't about limit CPU frequency, you could reduce your CPU load/consumption with an application like cpulimit (https://github.com/opsengine/cpulimit)

Hope this helps.

Comments

[Yannick Schneider]

So far this looks the best information out there: github.com/tiziw/iuvolt

[PawełG]

even better is this: github.com/georgewhewell/undervolt

[amanusk]

Thanks, but I was not interested in decreasing frequency. This could be done with for file in /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq; do echo "3500000" > $file; done I was specifically interested in decreasing voltage per frequency.

[FredericB]

I misunderstood, sorry. But TLP can control undervolting ability, but I couldn't find and tool to do it. However I found a good tutorial: ullright.org/ullWiki/show/ubuntu-undervoltage-linux-ppc

[Csaba Toth]

Do you have any suggestions for AMD CPUs/GPUs?

[BNDR]

Sorry, I am not an expert so I cannot draw recommendations. But I bet that there is someone out there with your same questions, the task is finding them!

[Suici Doga]

@CsabaToth turionpowercontrol works

[forgetso]

Seems like there is a solution for newer intel processors here