FreeBSD: Setting up CPU speed

Powerd settings (/etc/rc.conf):

# Powerd
powerd_enable=”YES”
powerd_flags=”-a adp -b adp -i 50 -r 75 -p 250″

Starting the process:

/etc/rc.d/powerd start

Parameters:

-a apd -> Operation mode while on AC power (adaptive)
-b apd -> Operation mode while on battery power (adaptive)
-i 50 -> Specifies the CPU load percent level when adaptive mode should begin to degrade performance to save power
-r 75 -> Specifies the CPU load percent level where adaptive mode should consider the CPU running and increase performance
-p 250 -> Specifies a different polling interval (in milliseconds) for AC line state and system idle levels

Others:
-m <freq> -> Minimum frequence reached by processor
-M <freq> -> Maximum frequence reached by processor
-n <op_mode> -> Used when the AC line is unknown