(Note that this post might look a bit intense, but it really isn't, it just has a few terminal commands)
The first step of this is to see what modes your CPU can use, so type
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governorsin a terminal. You should see a range of options, if not your CPU may not support scaling. My options are: "conservative ondemand userspace powersave performance".
At this point you should check the default for your CPU with:
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governorthis will tell you which mode your computer is currently using so you can switch back to it later.
You can then tell your computer to use a certain mode on the CPU. If you're just taking notes at work you probably need no more than powersave (or your CPU's equivalent).
cpufreq-selector -c 0 -g powersaveNote that you must put your core number after the -c. If your CPU has a dual-core processor (2 cores), run this twice with "-c 0" and "-c 1" (and do the appropriate for triple/quad cores).
And that's it! You can check how your CPU is doing with
cat /proc/cpuinfo | grep "cpu MHz"Try comparing it with performance mode to see the difference.