Want to change clock speed of Stater kit

Hi friends,

   I am working on AM335x starter kit. Its Presently running on 720 MHZ. I want to change Clock frequency

   of my board and want to check performance. but I am not aware of at which file I have to make changes

   for setting different clock frequencies. Please guide me.

   I used POWER Icon given on GUI of Starter board to change clock frequency but On rebooting

   board, It again changes to default 720 Mhz.

  Regards,

   Vishal,