PMSET(1)                     General Commands Manual                    PMSET(1)

     pmset – manipulate power management settings

     pmset [-a | -b | -c | -u] [setting value] [...]
     pmset -u [haltlevel percent] [haltafter minutes] [haltremain minutes]
     pmset -g [option]
     pmset schedule [cancel | cancelall] type date+time [owner]
     pmset repeat cancel
     pmset repeat type weekdays time
     pmset relative [wake | poweron] seconds
     pmset [touch | sleepnow | displaysleepnow | boot]

     pmset manages power management settings such as idle sleep timing, wake on
     administrative access, automatic restart on power loss, etc.

     Note that processes may dynamically override these power management
     settings by using I/O Kit power assertions.  Whenever processes override
     any system power settings, pmset will list those processes and their power
     assertions in -g and -g assertions. See caffeinate(8).

     pmset can modify the values of any of the power management settings defined
     below. You may specify one or more setting & value pairs on the command-
     line invocation of pmset.  The -a, -b, -c, -u flags determine whether the
     settings apply to battery ( -b ), charger (wall power) ( -c ), UPS ( -u )
     or all ( -a ).

     Use a minutes argument of 0 to set the idle time to never for sleep
     disksleep and displaysleep

     pmset must be run as root in order to modify any settings.

     displaysleep - display sleep timer; replaces 'dim' argument in 10.4 (value
     in minutes, or 0 to disable)
     disksleep - disk spindown timer; replaces 'spindown' argument in 10.4
     (value in minutes, or 0 to disable)
     sleep - system sleep timer (value in minutes, or 0 to disable)
     womp - wake on ethernet magic packet (value = 0/1). Same as "Wake for
     network access" in the Energy Saver preferences.
     ring - wake on modem ring (value = 0/1)
     powernap - enable/disable Power Nap on supported machines (value = 0/1)
     proximitywake - On supported systems, this option controls system wake from
     sleep based on proximity of devices using same iCloud id. (value = 0/1)
     autorestart - automatic restart on power loss (value = 0/1)
     lidwake - wake the machine when the laptop lid (or clamshell) is opened
     (value = 0/1)
     acwake - wake the machine when power source (AC/battery) is changed (value
     = 0/1)
     lessbright - slightly turn down display brightness when switching to this
     power source (value = 0/1)
     halfdim - display sleep will use an intermediate half-brightness state
     between full brightness and fully off  (value = 0/1)
     sms - use Sudden Motion Sensor to park disk heads on sudden changes in G
     force (value = 0/1)
     hibernatemode - change hibernation mode. Please use caution. (value =
     hibernatefile - change hibernation image file location. Image may only be
     located on the root volume. Please use caution. (value = path)
     ttyskeepawake - prevent idle system sleep when any tty (e.g. remote login
     session) is 'active'. A tty is 'inactive' only when its idle time exceeds
     the system sleep timer. (value = 0/1)
     networkoversleep - this setting affects how OS X networking presents shared
     network services during system sleep. This setting is not used by all
     platforms; changing its value is unsupported.
     destroyfvkeyonstandby - Destroy File Vault Key when going to standby mode.
     By default File vault keys are retained even when system goes to standby.
     If the keys are destroyed, user will be prompted to enter the password
     while coming out of standby mode.(value: 1 - Destroy, 0 - Retain)

     -g (with no argument) will display the settings currently in use.
     -g live displays the settings currently in use.
     -g custom displays custom settings for all power sources.
     -g cap displays which power management features the machine supports.
     -g sched displays scheduled startup/wake and shutdown/sleep events.
     -g ups displays UPS emergency thresholds.
     -g ps / batt displays status of batteries and UPSs.
     -g pslog displays an ongoing log of power source (battery and UPS) state.
     -g rawlog displays an ongoing log of battery state as read directly from
     -g therm shows thermal conditions that affect CPU speed. Not available on
     all platforms.
     -g thermlog shows a log of thermal notifications that affect CPU speed. Not
     available on all platforms.
     -g assertions displays a summary of power assertions. Assertions may
     prevent system sleep or display sleep. Available 10.6 and later.
     -g assertionslog shows a log of assertion creations and releases. Available
     10.6 and later.
     -g sysload displays the "system load advisory" - a summary of system
     activity available from the IOGetSystemLoadAdvisory API. Available 10.6 and
     -g sysloadlog displays an ongoing log of lives changes to the system load
     advisory. Available 10.6 and later.
     -g ac / adapter will display details about an attached AC power adapter.
     Only supported for MacBook and MacBook Pro.
     -g log displays a history of sleeps, wakes, and other power management
     events. This log is for admin & debugging purposes.
     -g uuid displays the currently active sleep/wake UUID; used within OS X to
     correlate sleep/wake activity within one sleep cycle.  history
     -g uuidlog displays the currently active sleep/wake UUID, and prints a new
     UUID as they're set by the system.
     -g history is a debugging tool. Prints a timeline of system sleeplwake
     UUIDs, when enabled with boot-arg io=0x3000000.
     -g historydetailed Prints driver-level timings for a sleep/wake. Pass a
     UUID as an argument.
     -g powerstate [class names] Prints the current power states for I/O Kit
     drivers. Caller may provide one or more I/O Kit class names (separated by
     spaces) as an argument. If no classes are provided, it will print all
     drivers' power states.
     -g powerstatelog [-i interval] [class names] Periodically prints the power
     state residency times for some drivers. Caller may provide one or more I/O
     Kit class names (separated by spaces). If no classes are provided, it will
     log the IOPower plane's root registry entry. Caller may specify a polling
     interval, in seconds with -i <polling interval>; otherwise it defaults to 5
     -g stats Prints the counts for number sleeps and wakes system has gone thru
     since boot.
     -g systemstate Prints the current power state of the system and available
     -g everything Prints output from every argument under the GETTING header.
     This is useful for quickly collecting all the output that pmset provides.
     Available in 10.8.

     hibernatemode supports values of 0, 3, or 25. Whether or not a hibernation
     image gets written is also dependent on the values of standby and

     For example, on desktops that support standby a hibernation image will be
     written after the specified standbydelay time. To disable hibernation
     images completely, ensure hibernatemode standby and autopoweroff are all
     set to 0.

     hibernatemode = 0 by default on desktops. The system will not back memory
     up to persistent storage. The system must wake from the contents of memory;
     the system will lose context on power loss. This is, historically, plain
     old sleep.

     hibernatemode = 3 by default on portables. The system will store a copy of
     memory to persistent storage (the disk), and will power memory during
     sleep. The system will wake from memory, unless a power loss forces it to
     restore from hibernate image.

     hibernatemode = 25 is only settable via pmset. The system will store a copy
     of memory to persistent storage (the disk), and will remove power to
     memory. The system will restore from disk image. If you want "hibernation"
     - slower sleeps, slower wakes, and better battery life, you should use this

     Please note that hibernatefile may only point to a file located on the root

     standby causes kernel power management to automatically hibernate a machine
     after it has slept for a specified time period. This saves power while
     asleep. This setting defaults to ON for supported hardware. The setting
     standby will be visible in pmset -g if the feature is supported on this

     standbydelayhigh and standbydelaylow specify the delay, in seconds, before
     writing the hibernation image to disk and powering off memory for Standby.
     standbydelayhigh is used when the remaining battery capacity is above
     highstandbythreshold , and standbydelaylow is used when the remaining
     battery capacity is below highstandbythreshold.

     highstandbythreshold has a default value of 50 percent.

     autopoweroff is enabled by default on supported platforms as an
     implementation of Lot 6 to the European Energy-related Products Directive.
     After sleeping for <autopoweroffdelay> seconds, the system will write a
     hibernation image and go into a lower power chipset sleep. Wakeups from
     this state will take longer than wakeups from regular sleep.

     autopoweroffdelay specifies the delay, in seconds, before entering
     autopoweroff mode.

     UPS-specific arguments are only valid following the -u option. UPS settings
     also have an on/off value. Use a -1 argument instead of percent or minutes
     to turn any of these settings off. If multiple halt conditions are
     specified, the system will halt on the first condition that occurs in a low
     power situation.

     haltlevel - when draining UPS battery, battery level at which to trigger an
     emergency shutdown (value in %)
     haltafter - when draining UPS battery, trigger emergency shutdown after
     this long running on UPS power (value in minutes, or 0 to disable)
     haltremain - when draining UPS battery, trigger emergency shutdown when
     this much time remaining on UPS power is estimated (value in minutes, or 0
     to disable)

     Note: None of these settings are observed on a system with support for an
     internal battery, such as a laptop. UPS emergency shutdown settings are for
     desktop and server only.

     pmset allows you to schedule system sleep, shutdown, wakeup and/or power
     on. "schedule" is for setting up one-time power events, and "repeat" is for
     setting up daily/weekly power on and power off events. Note that you may
     only have one pair of repeating events scheduled - a "power on" event and a
     "power off" event. For sleep cycling applications, pmset can schedule a
     "relative" wakeup or poweron to occur in seconds from the end of system
     sleep/shutdown, but this event cannot be cancelled and is inherently

     type - one of sleep, wake, poweron, shutdown, wakeorpoweron
     date/time - "MM/dd/yy HH:mm:ss" (in 24 hour format; must be in quotes)
     time - HH:mm:ss
     weekdays - a subset of MTWRFSU ("M" and "MTWRF" are valid strings)
     owner - a string describing the person or program who is scheduling this
     one-time power event (optional)

     -g with a 'batt' or 'ps' argument will show the state of all attached power

     -g with a 'pslog' or 'rawlog' argument is normally used for debugging, such
     as isolating a problem with an aging battery.

     boot - tell the kernel that system boot is complete (normally LoginWindow
     does this). May be useful to Darwin users.
     touch - PM re-reads existing settings from disk.
     noidle - pmset prevents idle sleep by creating a PM assertion to prevent
     idle sleep(while running; hit ctrl-c to cancel). This argument is
     deprecated in favor of caffeinate(8). Please use caffeinate(8) instead.
     sleepnow - causes an immediate system sleep.
     restoredefaults - Restores Energy Saver settings to their default values.
     (Like clicking "Restore Defaults" in Energy Saver GUI).
     displaysleepnow - causes display to go to sleep immediately.
     resetdisplayambientparams - resets the ambient light parameters for certain
     Apple displays.
     dim - deprecated in 10.4 in favor of 'displaysleep'. 'dim' will continue to
     spindown - deprecated in 10.4 in favor of 'disksleep'. 'spindown' will
     continue to work.

     This command sets displaysleep to a 5 minute timer on battery power,
     leaving other settings on battery power and other power sources

     pmset -b displaysleep 5

     Sets displaysleep to 10, disksleep to 10, system sleep to 30, and turns on
     WakeOnMagicPacket for ALL power sources (AC, Battery, and UPS) as

     pmset -a displaysleep 10 disksleep 10 sleep 30 womp 1

     Restores the system's energy settings to their default values.

     For a system with an attached and supported UPS, this instructs the system
     to perform an emergency shutdown when UPS battery drains to below 40%.

     pmset -u haltlevel 40

     For a system with an attached and supported UPS, this instructs the system
     to perform an emergency shutdown when UPS battery drains to below 25%, or
     when the UPS estimates it has less than 30 minutes remaining runtime. The
     system shuts down as soon as either of these conditions is met.

     pmset -u haltlevel 25 haltremain 30

     For a system with an attached and supported UPS, this instructs the system
     to perform an emergency shutdown after 2 minutes of running on UPS battery

     pmset -u haltafter 2

     Schedules the system to automatically wake from sleep on July 4, 2016, at

     pmset schedule wake "07/04/16 20:00:00"

     Schedules a repeating shutdown to occur each day, Tuesday through Saturday,
     at 11AM.

     pmset repeat shutdown TWRFS 11:00:00

     Schedules a repeating wake or power on event every tuesday at 12:00 noon,
     and a repeating sleep event every night at 8:00 PM.

     pmset repeat wakeorpoweron T 12:00:00 sleep MTWRFSU 20:00:00

     Prints the power management settings in use by the system.

     pmset -g

     Prints a snapshot of battery/power source state at the moment.

     pmset -g batt

     If your system suddenly sleeps on battery power with 20-50% of capacity
     remaining, leave this command running in a Terminal window. When you see
     the problem and later power and wake the computer, you'll be able to detect
     sudden discontinuities (like a jump from 30% to 0%) indicative of an aging

     pmset -g pslog


     All changes made through pmset are saved in a persistent preferences file
     (per-system, not per-user) at

     Scheduled power on/off events are stored separately in

     pmset modifies the same file that System Preferences Energy Saver modifies.

Darwin                          November 9, 2012                          Darwin