On Lenovo T400 and Ubuntu 10.10, I am using CPU Frequency Scaling Monitor 2.30.0 on the panel to show and control CPU frequency.

My CPU frequency by default will change according to load. But I want to make CPU work at the lowest level and so I choose 800 MHz in CPU Frequency Scaling Monitor. After a few seconds, however, it automatically changes back to Powersave or Performance mode which has automatic adjustment to CPU frequency.

I was wondering how to actually make CPU work at the lowest level? Thanks!

PS: On Acer Aspire 5000 and ubuntu 8.10, I can use CPU Frequency Scaling Monitor to control CPU frequency as I wish.


2 Answers 2


Follow the steps:

sudo apt-get install rcconf 
sudo rcconf

Search for


option and disable(un-check the check-box) it using space-bar.

  • @Tim .. Usefull answer?
    – Ilias
    Feb 14, 2011 at 10:23
  • @Ilias el Matani: Thanks! It doesn't solve the problem, as CPU Frequency Scaling Monitor still shows the freq of one CPU is set to "Performance" instead of "Ondemand" and is automatically change, while that of the other CPU is fixed at 800 MHz.
    – Tim
    Feb 14, 2011 at 12:25
  • Looks like I can only control frequency of one of the two CPUs via CPU Frequency Scaling Monitor.
    – Tim
    Feb 14, 2011 at 12:47
  • I think the question is not clear for me. If you disable 'ondemand' in rcconf the frequency of your CPU is not automatically being changed?
    – Ilias
    Feb 14, 2011 at 15:07
  • 1
    If I uncheck 'ondemand' in rcconf, the frequency of my CPUs is still automatically being changed.
    – Tim
    Feb 15, 2011 at 3:46

man cpufreq-set. Quick answer:


You might try the exact command:

sudo cpufreq-set -r -d 800MHz -u 1GHz

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