Ask HN: How to undervolt linux?

To "undervolt" and/or "underclock" a system reliably, the system must support it. Typically you want adjust the frequency scaling (if available), and there are multiple ways to do it, from simple sysctl commands to more complex dynamic frequency scaling daemons.

http://www.thinkwiki.org/wiki/How_to_make_use_of_Dynamic_Fre...

http://www.thinkwiki.org/wiki/How_to_reduce_power_consumptio...