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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 mode]
            [-p ival] [-P pidfile] [-r percent] [-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 minimum frequency to throttle down to.

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

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

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

     -P pidfile        Specifies an alternative file in which the process ID
                       should be stored.  The default is /var/run/powerd.pid.

     -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.

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

SEE ALSO
     acpi(4), apm(4), cpufreq(4)

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 11.0-PRERELEASE          July 4, 2013          FreeBSD 11.0-PRERELEASE

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY | AUTHORS | BUGS

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