Howto Change CPU Frequency Scaling in Ubuntu
The CPU Frequency Scaling Monitor provides a convenient way to monitor the CPU Frequency Scaling for each CPU.
Unfortunately, CPU frequency scaling can currently only be monitored on Linux machines that have support in the kernel. It can however, support the several generations of frequency scaling interfaces in the kernel.
When there is no CPU frequency scaling support in the system, the CPU Frequency Scaling Monitor only displays the current CPU frequency.
Right-click on your top or bottom bar, or wherever you want the applet to be you should see the following screen