Beginning with Linux Kernel 2.6, this functionality has been incorporated into the kernel in a safe manner for all supported processors. Try using powertweak for flexibility, or the automatic daemon cpufreqd instead..
The k6mult utility sets the CPU multiplier factor on AMD K6-III+ and K6-2+ processors featuring AMD PowerNow(tm).
The CPU clock speed is determined by multiplying this factor by the Front Side Bus (FSB) speed. You should use the k6mult utility if you want to increase the multiplier factor after boot to overcome boot-time CPU speed limitations in some BIOSs that do not recognize the K6-III+, or to lower the CPU speed after boot to save power.
k6mult comes with a command-line program of the same name to set the CPU multiplier factor immediately, and a boot-time service to set the parameter from a config file (/etc/k6mult.conf).
There are many other "tweaks" available for other processors, motherboard, and chipsets. If you have a need to tweak these other settings, or if you have a CPU other than the K6-III+, you should use PowerTweak instead of k6mult.
Most users should need only this file:
Installable file for RedHat Linux 7.1 k6mult-0.1-1.i586.rpm
Look here for source and other associated files.
Download and install the k6mult-0.1-1.i586.rpm RPM.
Test your desired value by becoming root, and running
/usr/local/sbin/k6mult with the desired CPU clock
multiplier as argument. Edit
/etc/k6mult.conf to set
the desired multiplier.
If you set the value too high without testing it, and your CPU
freezes once you reboot, restart and type
linux 1 and
/etc/k6mult.conf file again. (The k6mult starts
running at level 2.)
If you're having trouble following the above installation instructions, try these detailed installation instructions.
To uninstall k6mult, type the following:
$ su Password: # rpm -e k6mult
k6mult is available under GPL 2.0.
For more information on running and tuning Linux on the K6-III+/K6-2+, see JGott's Linux on the K6-2+/K6-III+ page. (Note that if you are using XFree86 4.0, it may do the
/proc/mtrr write-combining for your video card automatically, but it's worth checking.)