# Make sure your pc connect to mirror and get updated (don't forget to set up source.list file)
sudo apt-get update# Install sysstat package. This package contains complete-enough system performance tools for Linux
sudo apt-get install sysstat# We will use one of package contained in sysstat. It is sar (System Activity Reporter). To check CPU or processor speed per second, issue this command in your lovely Terminal
sar -m 1It is the mean speed of all of your processor cores. Enjoy!