Customers occasionally ask why sometimes when they go back to their Mac laptop after a break it wakes right up, but sometimes it takes much longer.
Mac laptops have two energy saving modes: Sleep and Standby. Sleep mode can be adjusted (such as how long before going into it) by the computer user in System Preferences under Energy Saver. It is a light energy-saving mode and does the following:
(On both laptops and iMacs both:)
- The microprocessor goes into a low-power mode
- Video output is turned off, and a connected display may turn off or enter its own idle state
- Apple-supplied hard disks spin down; third-party hard disks may spin down
(On laptops:)
- The Ethernet port turns off, if applicable (see note below)
- Expansion card slots turn off
- The built-in modem, if present, turns off (see note below)
- An AirPort card, if present, turns off (see note below)
- The USB ports only responds to the power key on an external keyboard (see below)
- The optical media drive, if present, spins down
- Audio input and output turns off
- Keyboard illumination, if a feature of your portable computer, turns off
The “Sleeping” device is easily awakened by tapping any key on the keyboard (except external keyboards which require tapping the power button on the keyboard) or opening the lid on laptops.
Standby is a more complete energy saving mode. The time the computer waits to go into it isn’t adjustable (at least through the User Interface) by users. Standby was introduced in 2012 Mac laptop models (except on MacBook Airs it was introduced in 2010) and is not available on iMacs. For 2012 to some 2013 models, the machine goes into Standby mode after a little over an hour in standard Sleep mode. In 2013 and later models, this was changed to three hours because of technological improvements that extended battery life overall.
To enter Standby, a laptop must be:
- Running on battery power (if it is a Mac laptop computer)
- Have no USB devices attached
- Have no Thunderbolt devices attached
- Have no SD card inserted
- Have no external display attached
A laptop can run up to thirty days in Standby before it needs to shut down. In Standby, the following additional components are powered down:
- The CPU
- RAM (after being copied to the hard drive)
Standby mode is more like being powered completely off than Sleep and therefore takes longer to “wake up.” So if you’ve been gone a few hours and it takes longer than usual to wake up, it’s because it’s gone into Standby mode.