This will works only for user who have rooted their phones and if you want to overclock the CPU i.e. increase maximum frequency of your CPU .You can also underclock your CPU and save a lot of battery.
As we say there is app available for every purpose in Android world so for the CPU purpose we have an app CPU tuner which is able to change CPU settings (both overclock and underclock ).you can Save battery or improve performance according to your preference.
1.Here is the Download link for CPU tuner:
2.After Installing ,open it and you will see certain tabs:-Current,Triggers,Profiles,Virtual Governers,Statistics,Profile Switch log
Drop comments about your experience and if you are facing any problems , do let us know