The purpose of this page is to provide general overview of power management in PacBSD.
Powerd(8) is a utility that monitors the system state, whether the system is running on battery or AC and current system load, and sets various power control options accordingly. Different power-saving modes can be set for operation on AC power (focus more on performance at the cost of consuming more power) or batteries (focus on less power consumption at the cost of performance).
Valid modes for powerd are
|maximum||Choose the highest performance values. May be abbreviated as max.|
|minimum||Choose the lowest performance values to get the most power savings. May be abbreviated as min.|
|adaptive||Attempt to strike a balance by degrading performance when the system appears idle and increasing it when the system is busy. It offers a good balance between a small performance loss for greatly increased power savings. May be abbreviated as adp.|
|hiadaptive||Like adaptive mode, but tuned for systems where performance and interactivity are more important that power consumption. It increases frequency faster, reduces frequency less aggressively, and will maintain full frequency for longer. Maybe abbreviated as hadp.|
The default mode is adaptive for battery power and hiadaptive for the rest. While this setting will work for a desktop, allowing the system to run at its full potential while being used and cut down on power consumption while idle. Laptop users may want to set power to operate at a more conservative mode while running off battery.
Configuration via FreeBSD-Init
If using the FreeBSD init system powerd is enabled/disabled and configured via
/etc/rc.conf. Configuration is done via two settings in
/etc/rc.conf the first, powerd_enable, takes a boolean "YES" or "NO", the second, powerd_flags, takes a string that is passed to
powerd as flags to set the different modes, frequencies, and CPU load percent levels to act on.
Example of setting powerd to use hiadaptive mode while on AC but use minimum when running off of batteries:
# sysrc powerd_enable="YES" # sysrc powerd_flags="-a hiadaptive -b minimum"
Another common setting for powerd is telling which mode to use incase it is unknown to the system if it is running off of AC or battery, this is done with the -n flag
# sysrc powerd_flags+="-n adaptive"
This tells powerd that we want it to use hiadaptive mode when on AC, minimum when on battery, and adaptive in times when/if it unable to detect the current power state.
To start powerd immediately without rebooting the system run:
service powerd start
Configuration via OpenRC
If using OpenRC as the init system, powerd is configured via
# Mode allowed: maximum, minimum, adaptive, hiadaptive # Default unless specified is hiadaptive powerd_ac_mode="hiadaptive" #powerd_battery_mode="minimum" # Additional arguments for powerd - see the man page for details powerd_args=""
This will cause powerd to operate in hiadaptive mode, at least while on AC. When OpenRC starts powerd it will pass the values set for
powerd_battery_mode to the
-b flags respectively.
If any other settings are desired to be set, such as setting a mode to use when powerd is unable to determine the current power state, these options are set in
# Mode allowed: maximum, minimum, adaptive, hiadaptive # Default unless specified is hiadaptive powerd_ac_mode="hiadaptive" powerd_battery_mode="minimum" # Additional arguments for powerd - see the man page for details powerd_args="-n adaptive"
Once powerd has been configured it can be enabled with
# rc-update add powerd default
and be started immediately with
# rc-service powerd start