What does Power Nap do?
If your Mac supports Power Nap, these activities can occur while your Mac is asleep:
- Mail receives new messages.
- Contacts keep up to date with changes made on other devices.
- Calendar receives new invitations and calendar updates.
- Reminders keep up to date with changes made on other devices.
- Notes keep up to date with changes made on other devices.
- Documents stored in iCloud keep up to date with changes made on other devices.
- Photo Stream keeps up to date with changes made on other devices.
- Find My Mac updates the location of the Mac, so you can find it while it's asleep.
- VPN on demand continues working so that your corporate email updates securely. (Power Nap supports VPN connections that use a certificate to authenticate, not VPN connections that require entering a password.)
- Mobile Device Management can remotely lock and wipe your Mac.
And these activities can occur while your Mac is asleep and plugged in to an AC power outlet:
- Software updates download.
- Mac App Store items (including software updates), download in the background.
- Time Machine performs backups.
- Spotlight performs indexing.
- Help Center content updates.
- Wireless base stations can wake your Mac using Wake on Wireless.
During Power Nap, your Mac plays no system sounds, including the Play Sound or Send Message feature of Find My Mac.
If your Mac has a hard drive (HDD) or a Fusion drive, you might hear sounds from the drive as it comes on during a Power Nap update, during operation, and when the drive turns off. You have the option to turn Power Nap off.
When Power Nap is turned on, your computer might be warm to the touch, even if it's sleeping. If your Mac exceeds a predefined temperature, Power Nap operations are suspended so that your Mac doesn't overheat. When your Mac wakes up, it’s ready to go.
Which Mac computers can use Power Nap?
You can use Power Nap on these Mac models:
- MacBook (Early 2015 and later)
- MacBook Air (Late 2010 and later)
Requires OS X Mountain Lion v10.8.2 and later
- MacBook Pro (all models with Retina display)
- Mac mini (Late 2012 and later)
- iMac (Late 2012 and later)
- Mac Pro (Late 2013)
Turn Power Nap on or off
The Power Nap setting is in the Energy Saver pane of System Preferences.
Choose Apple menu > System Preferences, then click Energy Saver. Use the "Enable Power Nap" checkbox to turn Power Nap on or off. The default setting is on if your desktop Mac uses flash storage (not including Fusion Drive).
Choose Apple menu > System Preferences, then click Energy Saver.
- Click the Battery tab, then use the "Enable Power Nap while on battery power" checkbox to control whether your Mac uses Power Nap while on battery power. The default setting is off.
- Click the Power Adapter tab, then use the "Enable Power Nap while plugged into a power adapter" checkbox to control whether your Mac uses Power Nap while using AC power. The default setting is on.
Power Nap responds to your battery power state
The year your notebook computer was released determines how Power Nap responds to your battery power state.
Computers with 2013 or a later year in the model name use Power Nap until the battery is drained. Computers with 2012 or an earlier year in the model name suspend Power Nap if the battery has a charge of 30% or less. Power Nap resumes when you connect to AC power.
To increase battery life while using Power Nap, disconnect any USB, Thunderbolt, or FireWire devices that may draw power from the computer. Learn more about maximizing battery life.
Power Nap checks for updates at specific intervals
When your computer isn't connected to AC power, Power Nap communicates and transfers data for only a few minutes per Power Nap cycle. When connected to AC power, communications and data transfers are continuous.
- Mail, Notes, Contacts, Calendar, Reminders, Photo Stream, Find My Mac, and iCloud documents are checked every hour. To receive updates during Power Nap, Mail and Notes must be open before your Mac sleeps.
- Time Machine backups are attempted hourly until a successful backup has been completed.
- Software Updates are checked daily.
- Mac App Store downloads are checked once a week.