How to Optimize Your Mac With Power Management Settings

Default power management settings coming with your Mac

Every Mac comes pre-programmed with power management settings that can be checked by hitting the Apple icon and then selecting About This Mac > System Information > Power > System Power Settings. This is where you’ll find the power management settings for both AC and battery. This section clarifies how long a period of inactivity it will take before the display is put to sleep (which can be adjusted in the Energy Saver screen) or before the system enters standby (if this feature is enabled). Here is where you’ll also find information about the type of hibernation enabled on the Mac.

The type of hibernate mode determines how the Mac enters Safe Sleep. You may already know that leaving the computer idle for a while triggers different modes to conserve energy, covering standby mode, hibernate mode, safe sleep and sleep mode.

How to customize the Mac’s power management settings

This isn’t something the average user will start playing around with, but if you understand what the different settings mean then it’s possible to optimize the Mac’s performance by applying different power management settings.

You may recall that waking the computer is sometimes slower than usual, so if you want to speed your Mac up then customizing its hibernate mode with the help of power management settings is a good place to start.

The steps are similar to what we’ve already shown with standby mode, but this time the target is hibernate mode:

Understanding the different hibernate mode settings

Hibernate mode 0 is the default on desktop Macs, and it means that the system won’t write off the content of the RAM to the disk, meaning that data is lost if there is a loss of power.

Hibernate mode 3 is the default on portable Macs, and it means the system will store a copy of the memory on the internal disk (see sleepimage files) and continue to power the memory during sleep mode. The Mac will still wake from memory unless a loss of power forces it to restore from a disk image.

Hibernate mode 25 can be set only by the computer administrator using Terminal via the “pmset” command. By switching to mode 25 the system will write the data from the RAM to SSD disk and power down. This affects the overall sleep-to-wake performance (as in it will become slower to wake) but it contributes to an extended battery life overall.

Now it’s your time to pick the setting that’s appropriate for your own workflow. For example, if your Mac’s hibernate mode was set to 0 then you can change it to 3 by running the following command in Terminal:pmset hibernatemode 3

That’s about it.

By moving down to 0 you will regain gigabytes of space as the Mac won’t need to create a sleep image – a file where it writes off memory before going into hibernate mode – and the wake-up time will be much shorter. That, however, also means you’ll lose all your data in the case of a power failure or if the Mac runs out of battery life.