How does display resolution and scaling work on macOS?

[ProQuiz]

I have a MacBook Pro 14" which has a native resolution of 3024 x 1964. However, I just noticed in Display settings that the set default resolution is 1512 x 982. How does that work? Does this mean I am not getting the "full benefit" of my display? I know that resolution and scaling works differently on macOS than on Windows so could someone explain what's going on here? In this 1512 x 982 default mode, if I watch a 1080p or 4K video, will I not get their native resolutions?

On Windows, if you have a 4K monitor you set the resolution to 4K. If you want to scale the resolution you select 125%, 150%, etc. Is it the other way around or something on macOS?

 

[Moncler]

Since retina is 2x, that would mean its default is 1280x800 (832)

The 14" MBP is 3024-by-1964 native, so it's 1512 x 982 at "default"

See https://9to5mac.com/2021/10/19/new-macbook-pro-screen-resolution-options/

 

[K two]

I have a MacBook Pro 14" which has a native resolution of 3024 x 1964. However, I just noticed in Display settings that the set default resolution is 1512 x 982. How does that work? Does this mean I am not getting the "full benefit" of my display? I know that resolution and scaling works differently on macOS than on Windows so could someone explain what's going on here? In this 1512 x 982 default mode, if I watch a 1080p or 4K video, will I not get their native resolutions?

On Windows, if you have a 4K monitor you set the resolution to 4K. If you want to scale the resolution you select 125%, 150%, etc. Is it the other way around or something on macOS?

Go native and SEE what you get? 3024 x 1964 is 200% or 2X native. But you knew that.

 

[joevt]

The 1512 x 982 mode is actually 3024 x 1964. MacOS is drawing text and objects using twice as many pixels vertically and horizontally (4 times as many pixels total) than it would use for a real or scaled 1512 x 982 mode.

You'll see this as "Looks like 1512 x 982" in the Displays preferences panel. SwitchResX will show it as a HiDPI mode. The Displays preferences panel has an option to unhide low resolution modes (modes that are not HiDPI).

Usually scaling by the GPU is used for any mode that doesn't match the 3024 x 1964 resolution of the display. The "Looks like 1512 x 982" is not a scaled mode since it matches the 3024 x 1964 resolution of the display.

The GPU could generate a mode that is not 3024 x 1964 which would then need to be scaled by the display (if the display has its own scaler).

To know if a mode is HiDPI or not, scaled by the GPU, or scaled by the display, you would need to use a utility like SwitchResX to view the timing info of the mode (pixel clock, active pixels, etc.).

For example, if you have a 4K display, and want to display 2560x1440, then there are a few ways to do that.
1) 2560x1440 framebuffer, scaled by the GPU to produce a 4K timing for DisplayPort output.
2) 2560x1440 framebuffer, to produce a 1440p timing for DisplayPort, scaled by the display to 4K.
3) 2560x1440 HiDPI mode, uses a framebuffer of 5120x2880, scaled by the GPU to produce a 4K timing for DisplayPort output.
4) 2560x1440 HiDPI mode, uses a framebuffer of 5120x2880 to produce a 5K timing for DisplayPort, scaled by the display down to 4K.

Some people might have a 5K display and select a 2560x1440 HiDPI mode, but it outputs as 4K from the GPU because they don't have the correct connection to the 5K display. The display scales up the 4K to 5K. MacOS won't notify the user of this issue. Some users don't even notice that they're not getting a 5K signal especially if they haven't seen 5K before.

 

[lostless]

mac os works like this, it has a logical size and a High DPI equivalent, which is 4 times the resolution of the logical resolution. The thing is is that the GUI is tied to the logical size as far as text and window sizes. It doesnt have a separate scale for that like windows. So your mac is logically, 1512 x 982 as far as scaling and size of text and icons and what not but is actually displaying the higher dpi, so your 1080P videos will show the full resolution. The 4K videos will be limited to the 3K display your mac has.
Now here's the somewhat bad part about how mac handles resolutions. If you are using a, let's say, an external 4K monitor, the logical size is 1080P, which may look too cramped on a 27inch monitor. But since the GUI is tied to resolution, If you scale the GUI to look like a 1440p (5k high dpi) monitor, the mac will actually render a full 5K image and then in the GPU scale to 4K. The issue is that the scaling down may cause some blurring. But in all honesty thats how i run my 4K monitor and it's fine. I can tell that there is a little bit blurring, but if your not looking for it or what to look for, its not noticeable. Also the mac warns you it could cause some performance issues.