How to turn off an external display without disconnecting?

Solution 1:

There are two solutions I can think of:

• SwitchResX
• Power plug adapter with remote control

SwitchResX has a number of features including "disable display" which should deactivate it until the software turns it back on. From their FAQ:

SwitchResX includes a function to remove a display from the System's list of managed display. This means the display in question, once deactivated, will not be visible from the System or from any application. Only SwitchResX will be able to activate the display again.

Another simple solution is to use a power plug with a remote switch. It's an easy, non-invasive solution that will get the job done without having to install software or have daemons running that could interfere with your display. macOS will not detect the display if the power is cut (though it will if it's in "standby" or "sleep")

Both solutions cost about the same (less than $20USD). SwtichResX has a 10 day free trial and the power adapter comes with a 30 day return. The software has the benefit of being elegant; but the switch, though a bit crude, has the advantage of you knowing for sure you display is disabled because it's physically off.

Solution 2:

While not the best option for the op having to physically disable the display I think that is the best option. I was able to get a Geeni multiplug that I can enable each monitor individually through Google Home.

I tried the SwitchResX suggested here and it was the worst experience. I have a 2017 Macbook Pro with 4 monitors connected plus the internal display and as soon as I disabled one of the monitors, SwitchResX turned off every display and no matter what I did they never re-enabled. In the end I unplugged the 4 monitors which enabled the internal display. Then I plugged them again which did nothing and as I was looking for solutions each monitor slowly started coming back 2-3 minutes apart from each other.

Needless to say I ended uninstalling SwitchResX and sticking to using the multiplug through voice.

If you need one just search amazon for WiFi outlet. I found mine at Marshalls but I haven't seen one there ever again.

Solution 3:

If the work is not GPU intensive you might try to manually switch from the Discrete graphic card to the Integrated (Intel HD Graphics). Should work for all 2008-2012, 15-17" dual-GPU MacBook Pros. By installing gfxCardStatus you can do this from the menu bar.