I want my Macbook display to show nothing when I connect to a monitor

[stanleystf]

On Windows, after I connect my laptop to an external monitor, I press Windows key+P on keyboard and I can choose what my laptop display shows. There's an option that I can choose that the laptop's display shows nothing. Can I do that on Macbook pro M1 16inch?

Also, can I close the Macbook lid when I'm using a monitor?

 

[Amethyst1]

There's an option that I can choose that the laptop's display shows nothing. Can I do that on Macbook pro M1 16inch?

DisableMonitor

Also, can I close the Macbook lid when I'm using a monitor?

Yes, if you have an external keyboard and/or mouse connected. That's called Clamshell mode.

 

[stanleystf]

DisableMonitor


Yes, if you have an external keyboard and/or mouse connected. That's called Clamshell mode.

I realized that my Macbook starts charging when I connected the monitor to it via USB C cable.

I have to questions?

1. If I do this all the time, is that potentially going to damage the Macbook's battery? Since it's being charged by the monitor all the time.

2. Is it okay for the Macbook lid to be closed all the time? I don't do anything heavy right now but could it potentially cause overheating issues?

 

[Amethyst1]

1. If I do this all the time, is that potentially going to damage the Macbook's battery? Since it's being charged by the monitor all the time.

There is software that stops charging at, say, 90% if you’re weary of always charging it fully. It doesn’t matter whether you’re using the monitor or the MacBook’s power adapter.

2. Is it okay for the Macbook lid to be closed all the time? I don't do anything heavy right now but could it potentially cause overheating issues?

MacBooks are designed to be used that way so I wouldn’t worry unless you were doing extremely intensive tasks all the time.

 

[stanleystf]

Thank you!

One more thing: I can't change the font/folder/icon size when I close the Macbook's lid and the monitor becomes the main display:

To make the icons and texts bigger, I have to reduce the resolution which reduces quality.

Is there a way I can change text/icon size when the monitor becomes the main display, and not change the resolution?

 

[Amethyst1]

Is there a way I can change text/icon size when the monitor becomes the main display, and not change the resolution?

What you're getting on the MacBook's internal "Retina Display" are so-called scaled HiDPI modes.
In order for macOS to activate those on an external monitor, the external monitor needs to have a resolution of "4K" (3840×2160) or higher. Your monitor's resolution is 2560×1440; that's not sufficient.
You can try enabling those HiDPI modes anyway using SwitchResX, by adding custom scaled modes.

You can change icon size in Finder windows and font size in applications, but that's not what you're referring to, is it?. You're referring to the five options you get for the MacBook's screen that go from "Larger Text" to "More Space". These are scaled HiDPI modes.

 

[stanleystf]

What you're getting on the MacBook's internal "Retina Display" are so-called scaled HiDPI modes.
In order for macOS to activate those on an external monitor, the external monitor needs to have a resolution of "4K" (3840×2160) or higher. Your monitor's resolution is 2560×1440; that's not sufficient.
You can try enabling those HiDPI modes anyway using SwitchResX, by adding custom scaled modes.

You can change icon size in Finder windows and font size in applications, but that's not what you're referring to, is it?. You're referring to the five options you get for the MacBook's screen that go from "Larger Text" to "More Space". These are scaled HiDPI modes.

Yes when the Macbook display is the main display, I get these:

If I get a 4K monitor, I will get those 5 options when the monitor becomes the main display? Because when I go to lower resolutions, the icons and texts get bigger.

If I choose to mirror the displays and tick "scaled", then I get massive black bars on the sides of the Monitor.

 

[Amethyst1]

If I get a 4K monitor, I will get those 5 options when the monitor becomes the main display?

In that case, you will get them no matter what.

If I choose to mirror the displays and tick "scaled", then I get massive black bars on the sides of the Monitor.

If both displays are mirrored, the MacBook's ≈16:10.4 mode (you have the Notch, right?) is "squished" onto the 16:9 monitor, resulting in vertical black bars. This will also happen with a "4K" monitor, since it'll also have a 16:9 aspect ratio.

 

[stanleystf]

Right now, with this 2K monitor, how can I make texts and icons bigger? I installed SwitchX and it only gives me the option of changing the resolution. Again, if I choose a lower resolution, say 720p, the icons and texts become bigger but the quality decreases.

In that case, you will get them no matter what.


If both displays are mirrored, the MacBook's ≈16:10.4 mode (you have the Notch, right?) is "squished" onto the 16:9 monitor, resulting in vertical black bars. This will also happen with a "4K" monitor, since it'll also have a 16:9 aspect ratio.

 

[Amethyst1]

Right now, with this 2K monitor, how can I make texts and icons bigger? I installed SwitchX and it only gives me the option of changing the resolution. Again, if I choose a lower resolution, say 720p, the icons and texts become bigger but the quality decreases.

It's a bit complicated due to how scaling works on macOS.

You need to add a custom scaled mode to get a HiDPI mode.

If you want to make everything just slightly bigger, I'd say try a 2048×1152 HiDPI mode. To do this, you need to go to the "Custom Resolutions" tab and click "+". Select "Scaled" and enter 4096 pixels by 2304 lines.
Yes, really. The scaled mode you create needs to be twice as wide and twice as tall as the HiDPI mode you want.
Click "OK" and "Activate immediately", then go to the "Current Resolutions" tab and look for the 2048×1152 HiDPI mode. Click on the radio button next to it to activate it and see if it works and is good enough.

If you want stuff to be even bigger, a 1280×720 HiDPI mode should be available out of the box in SwitchResX' "Current Resolutions" tab.

If that is too big, try something in between. A custom scaled mode of 3200 pixels by 1800 lines will give you a 1600×900 HiDPI mode, for instance.

 

[stanleystf]

If you want to make everything just slightly bigger, I'd say try a 2048×1152 HiDPI mode. To do this, you need to go to the "Custom Resolutions" tab and click "+". Select "Scaled" and enter 4096 pixels by 2304 lines.
Yes, really. The scaled mode you create needs to be twice as wide and twice as tall as the HiDPI mode you want.
Click "OK" and "Activate immediately", then go to the "Current Resolutions" tab and look for the 2048×1152 HiDPI mode. Click on the radio button next to it to activate it and see if it works and is good enough.

I tried this and it did work. However, the quality and sharpness decreased! Let's say I choose 720p resolution. Does that decrease the quality of the movies I watch?

Are you sure if I get a 4K monitor, these issues will go away? I can change the icon size and text without changing the resolution?

 

[Amethyst1]

I tried this and it did work.

What mode did you create? Did you enable the corresponding HiDPI mode?

However, the quality and sharpness decreased!

What mode are you using? It’s possible that the HiDPI modes don’t look as good as you might expect because of the monitor’s “low” resolution and pixel density.

Let's say I choose 720p resolution. Does that decrease the quality of the movies I watch?

If you choose non-HiDPI 720p, the quality of the monitor’s image will decrease. That always happens if you use an LCD at a lower than native resolution.
If you choose HiDPI 720p, it won’t because that’s the “perfect” HiDPI mode for your 1440p monitor, and the monitor still runs at native resolution.
It doesn’t affect the quality of movies.

Are you sure if I get a 4K monitor, these issues will go away? I can change the icon size and text without changing the resolution?

The “4K” monitor will always be driven at its native resolution regardless of the HiDPI mode you use. Out of the box, no messing around required.

 

[stanleystf]

What mode did you create? Did you enable the corresponding HiDPI mode?


What mode are you using? It’s possible that the HiDPI modes don’t look as good as you might expect because of the monitor’s “low” resolution and pixel density.


If you choose non-HiDPI 720p, the quality of the monitor’s image will decrease. That always happens if you use an LCD at a lower than native resolution.
If you choose HiDPI 720p, it won’t because that’s the “perfect” HiDPI mode for your 1440p monitor, and the monitor still runs at native resolution.
It doesn’t affect the quality of movies.


The “4K” monitor will always be driven at its native resolution regardless of the HiDPI mode you use. Out of the box, no messing around required.

Thank you very much! I chose HiDPI mode and everything looks good now.

To have "720p HiDPI", do I need to have SwitchRX?

Because it's a trial and I have 10 days left.

 

[Amethyst1]

To have "720p HiDPI", do I need to have SwitchRX?

It should not be necessary because that “perfect” mode is offered out of the box by macOS. In case the mode does disappear after uninstalling SwitchResX — macOS usually hides HiDPI modes on sub-4K monitors —, you can try e.g. RetinaDisplayMenu to re-enable it: Select the 720p mode that has a lightning bolt next to it.