POWERD(8)               FreeBSD System Manager's Manual              POWERD(8)

NAME
     powerd - system power control utility

SYNOPSIS
     powerd [-a mode] [-b mode] [-i percent] [-M freq] [-m freq] [-N]
            [-n mode] [-P pidfile] [-p ival] [-r percent] [-s source] [-v]

DESCRIPTION
     The powerd utility monitors the system state and sets various power
     control options accordingly.  It offers power-saving modes that can be
     individually selected for operation on AC power or batteries.

     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 than power consumption.
                 It increases frequency faster, reduces frequency less
                 aggressively, and will maintain full frequency for longer.
                 May be abbreviated as hadp.

     The default mode is adaptive for battery power and hiadaptive for the
     rest.

     powerd recognizes these runtime options:

     -a mode     Selects the mode to use while on AC power.

     -b mode     Selects the mode to use while on battery power.

     -i percent  Specifies the CPU load percent level when adaptive mode
                 should begin to degrade performance to save power.  The
                 default is 50% or lower.

     -M freq     Specifies the maximum frequency to throttle up to.

     -m freq     Specifies the minimum frequency to throttle down to.

     -N          Treat "nice" time as idle for the purpose of load
                 calculation; i.e., do not increase the CPU frequency if the
                 CPU is only busy with "nice" processes.

     -n mode     Selects the mode to use normally when the AC line state is
                 unknown.

     -P pidfile  Specifies an alternative file in which the process ID should
                 be stored.

     -p ival     Specifies a different polling interval (in milliseconds) for
                 AC line state and system idle levels.  The default is 250 ms.

     -r percent  Specifies the CPU load percent level where adaptive mode
                 should consider the CPU running and increase performance.
                 The default is 75% or higher.

     -s source   Enforces method for AC line state refresh; by default, it is
                 chosen automatically.  The set of valid methods is sysctl,
                 devd and apm (i386 only).

     -v          Verbose mode.  Messages about power changes will be printed
                 to stdout and powerd will operate in the foreground.

FILES
     /var/run/powerd.pid  The default PID file.

SEE ALSO
     acpi(4), apm(4), cpufreq(4), rc.conf(5)

HISTORY
     The powerd utility first appeared in FreeBSD 6.0.

AUTHORS
     Colin Percival first wrote estctrl, the utility that powerd is based on.
     Nate Lawson then updated it for cpufreq(4), added features, and wrote
     this manual page.

BUGS
     The powerd utility should also power down idle disks and other components
     besides the CPU.

     If powerd is used with power_profile, they may override each other.

     The powerd utility should probably use the devctl(4) interface instead of
     polling for AC line state.

FreeBSD 13.1-RELEASE-p6        November 6, 2021        FreeBSD 13.1-RELEASE-p6