The Display Sleep Vector
By default, macOS is aggressively configured to conserve power. When your Mac’s display turns off due to inactivity, the operating system almost immediately places the entire computer into a deep sleep state. This behaviour pauses active downloads, disrupts ongoing network rendering tasks, and disconnects SSH sessions. For users running continuous background operations, this automated power management is highly disruptive.
How to Prevent System Sleep While the Display is Off
You can configure macOS to keep the core system active and connected to the network even when the screen is powered down.
1. Click the Apple Logo in the top-left corner of the menu bar.
2. Select System Settings (or System Preferences on older versions of macOS).
3. In the left-hand sidebar, scroll down and click on Displays.
4. Click the Advanced button at the bottom of the Displays menu.
5. Locate the toggle labelled Prevent automatic sleeping when the display is off.
6. Switch the toggle to the On position.
7. Click Done to save your changes.
Your Mac will now continue executing background tasks and maintaining network connections, even when the screen goes dark to save energy.