Arch: change cpu frequency

pacman -S cpufrequtils

add to /etc/rc.conf

MODULES=(acpi-cpufreq) #there may be another modules

DAEMONS=(cpufreq) # there may be another demons

edit /etc/conf.d/cpufreq

governor="ondemand" #dynamic mode

modprobe acpi-cpufreq

/etc/rc.d/cpufreq restart