From http://linux.powertweak.com/overview.html:
There exists a tool for the Microsoft Windows platform called
Powertweak.
This tool provides features for tuning of system hardware such
as CPU and connected devices
This page is intended for an audience of Linux users who want a
tool to provide the same functionality.
Unlike the Microsoft Windows version, this port will be
Opensourced, GPL, and 100% free.
Due to the way that Linux works, such a tool can only be run
during startup, or by a root user.
This means that the Linux version will initially be without GUI
support.
Although it is planned that future versions will provide a GUI
based configuration tool for adjusting the config files.