I have a problem when I lock my MacOS Ventura MBP. My external monitors take an eternity to wake up after being asleep. I want to log back in and return to work immediately. The built-in display wakes almost immediately.

I've tried using the "prevent automatic sleeping on power adapter when the display is off" option. It doesn't work. When I lock the screen, all the displays are immediately turned off. I have also played around with screensaver settings to no avail.

How do I prevent my displays from sleeping? I don't mind if the built-in display sleeps.

Edit for adding detail

It seems to me that it is some power-saving feature of Ventura to immediately put all displays to sleep when the system is locked.

The screensavers will start if I leave my system without locking, but I always lock my screen when I get up and leave my computer (I'm in an office environment). If I leave the machine like this, the screen lock will eventually be activated (the screens don't turn off). However, if I hit ctrl-command-q, the screens always turn off immediately. Here are my lock screen settings:

Lock Screen Settings

The external monitors are the same and details are below. One is attached via the HDMI port on the side of the M1 MBP. The other is attached via Apple's own TB4 to USB/HDMI/TB4 dongle.

  Resolution:   5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
  UI Looks like:    2560 x 1440 @ 60.00Hz
  Main Display: Yes
  Mirror:   Off
  Online:   Yes
  Rotation: Supported
  • 1
    This is going to very difficult to diagnose without knowing the make/model of the monitors, how they are connect, whether or not you're using adapters like HDMI, DVI, or something else and their makes/models. Can you post and edit with this additional information?
    – Allan
    Commented Jun 23, 2023 at 12:58
  • Isn't this driven entirely by the Mac itself. If it drops the external signal, the displays will sleep. Anecdotally, I have one app [Cubase, but not really important] that if it's running, the screensaver will activate [which it doesn't normally, as I have my displays set to sleep at the same time as screensaver comes on.] If I then leave it long enough to auto-lock, then wake it, the login screen actually breaks through the screensaver rather than it switching off the saver & presenting the normal login screen. The displays in this instance never sleep, even though the Mac is locked.
    – Tetsujin
    Commented Jun 23, 2023 at 15:24

1 Answer 1


I found a method to prevent my displays from sleeping when I lock the screen. I would have preferred a native method, but the App called "Amphetamine" prevents my screens from sleeping.

Thanks William Gustafson for creating such an awesome app and thanks again for making it free.

  • Is the builtin caffeinate able to hold an assertion that achieves your goal?
    – hym3242
    Commented Jun 7 at 4:14

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