cpupower

sudo apt-get install linux-tools-$(uname -r)      # to install

Info

cpupower -c 0,1,2,3 frequency-info
cpupower -c 0,1,2,3 frequency-info | grep CPU.*Hz    # show current freq

Setting

powersave

#!/bin/bash
sudo cpupower frequency-set -d 800 -g powersave

performance

#!/bin/bash
sudo cpupower frequency-set -d 800 -g performance

ondemand

#!/bin/bash
sudo cpupower frequency-set -d 800 -g ondemand