1. First go to '/etc/' and find the file 'cpufreqd.conf' and make a backup of it. To do so you can copy the file and paste it in your Desktop.
2. You can manually change to 'On Demand' mode entering the following command in your terminal:
sudo cpufreq-set -c 0 -g ondemand
But this is a temporary change. If your restart cpufreqd you will see that it reverts back to 'Performance.' Try it using the following command:
sudo service cpufreqd restart
So to make the change permanent goto Step 3:
3. Open your terminal (CTRL+ALT+T) and type the following command:
sudo gedit /etc/cpufreqd.conf
On line 4 & line 5 you should see a Note as below(to view line numbers in gedit, Click on Edit - Preferences - Under View - Check Display line numbers:
# Note: ondemand/conservative Profiles are disabled because # they are not available on many platforms.
Now uncomment all the lines from line number 28 to line number 40 as below:
[Profile] name=On Demand High minfreq=40% maxfreq=100% policy=ondemand [/Profile] [Profile] name=On Demand Low minfreq=20% maxfreq=80% policy=ondemand [/Profile]
Also uncomment the lines from line number 71 to 83.
In line 92 change 'Performance High' to 'On Demand High' as below:
profile=On Demand High
Now SAVE your file and RESTART as stated above.
You should now see that your cpufreq mode changes to 'On Demand' if it was in 'Performance' or continue to stay in 'On Demand' mode.