General standby information
Mac notebook and desktop computers have a power standby feature that conserves energy. During standby, the state of your session is saved to flash storage (SSD). Then, the power turns off to some hardware systems such as RAM and USB buses.
Standby extends how long a notebook computer can stay asleep on battery power. A notebook with a fully charged battery can remain in standby for up to thirty days without being plugged in to power.
Macs that can use standby
- MacBook (Retina, 12-inch, Early 2015)
- MacBook Pro (Retina, 13-inch, Late 2012 and later)
- MacBook Pro (Retina, 15-inch, Early 2013 and later)
- MacBook Pro (Retina, Mid 2012)
- MacBook Air (Mid 2010 and later)
- SSD and Fusion drive versions of Mac mini (Late 2012 and later)
- SSD and Fusion drive versions of iMac (Late 2012 and later)
- Mac Pro (Late 2013)
Mac computers manufactured in 2013 or later enter standby after being in sleep mode for three hours. Earlier models enter standby after just over an hour of sleep. Put your computer to sleep by choosing Sleep from the Apple () menu.
Other requirements to enter standby are different for notebooks and desktops.
- Notebooks need to be running on battery power. It also must not have any external connections (such as Ethernet, USB, Thunderbolt, SD card, displays, Bluetooth, and so on).
- Desktops must have no external media mounted (such as SD cards, USB, or Thunderbolt storage devices).
To exit standby, do any one of the following:
- Press a key
- Click the trackpad or mouse
- Open the lid on a notebook
- Plug in a power adapter on a notebook
- Plug in a display
When the computer exits standby, the state of the system stored on the flash storage is used to restore the system to its pre-standby state. The computer returns to full operation within a few seconds.
If you leave a notebook in standby long enough for the battery to deplete fully, the computer will shut down. You can recover your computer to its pre-standby state and any unsaved work should not be lost. To exit standby at this point, attach the computer to a power source and press the Power button.
If exiting standby or waking is slow
Your Mac might seem to be taking longer then usual to start up or seem slow to wake from sleep or standby. If this is the case, make sure the startup disk is set correctly in the Startup Disk preferences.
- Choose System Preferences from the Apple () menu.
- Choose Startup Disk from the View menu.
- Make sure your internal drive is selected.