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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.
-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 /etc/rc.d/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 14.0-RELEASE-p11 February 25, 2023 FreeBSD 14.0-RELEASE-p11