Macbook Pro 2019 doesn't recognize 4k TV's native resolution as 4k

[UncleLeoTheDad]

Full disclosure: I also posted this at discussions.apple.com, but not getting any bites so far - https://discussions.apple.com/thread/253949996

I have a MacBook Pro 2019 and a 50" Hisense H8G (https://www.hisense-usa.com/tv-and-...quantum-4k-uled-hisense-android-smart-tv-2020). I connect the Macbook to the H8G via an Anker USB-C to HDMI adapter (https://www.amazon.com/gp/product/B07THJGZ9Z), though I've also tried 2 of Apple's USB-C Multiport Adapters (A1621).

I am running MacOS Monterey 12.4.

The (perceived?) problem: given my TV is 4k, I would expect MacOS to recognize my display as 4K natively. In some cases, it does:

Also, when I connect my Macbook to the display, the H8G reports that it is operation in 2160P with HDR10, which sounds right.

However, when I go into Display Preferences, you can see it thinks 1080 is the default resolution for this display:

Why do I care? Well, I've noticed WindowServer process has been sucking up more than 50% of CPU and read that scaling can be a major factor. This led me to look at my scaling settings and wondering why Display Settings is forcing me to scale to 2160 when the monitor should be doing so natively.

Any ideas?

Thanks!

 

[w5jck]

Apple does something similar itself. A retina display is perhaps shown to be (advertised as) a 2560 x 1600 screen resolution. However, in reality Apple uses 1280 x 800 resolution and upscales it to 2560 x 1600 pixels. So the resolution is 1280 x 800 but it is upscaled to use all 2560 x 1600 pixels. 4K TVs do this with full HD (1920 x 1080) resolution). They upscale the FHD resolution to use all 3840 x 2160 pixels. For actual 4K resolution they don't need to upscale. My guess is that your MacBook Pro is seeing you need to fill 3840 x 2160 pixels on your TV, and it is doing its upscaling routine to upscale 1920 X 1080 to fill the 3840 x 2160 pixels. This gives you text which you can actually read. If the MacBook Pro merely sent 3840 x 2160 resolution to the TV, the text and interface portions would be very tiny and difficult to read, especially across a room. The MacBook Pro should be able to send 4K resolutions to your TV, or scale it using a few different resolution up to 4K.

The simple fact is, most people who hook up a 4K monitor or TV to a Mac will wind up scaling a lesser resolution up to 4K pixels if they are running apps and doing "computer" things. If they are watching 4K video, then switching to 4K resolution makes sense. Bottomline, resolution doesn't equate to pixel numbers. You can easily upscale FHD, QHD etc. to 3840 x 2160 pixels to be able to easily see the text and user interface. However, upscaling requires processor usage, so it can take a hit.

 

[w5jck]

BTW, I have a Samsung 27 inch 4K monitor connected to my MacBook Air M1 2020. Even though I sit within 30 inches of the monitor, for most computer tasks I have to set the scaling to 2560 x 1440 resolution then have it upscaled to 3840 x 2160 pixels if I want to comfortably read text on it and see the interface. As you can see from the image below, choosing the "More Space" option (3840 x 2160 resolution) would make reading text very difficult and cause eyestrain. However, when I watch video on the monitor I temporary select the More Space option.

 

[galad]

1920x1080 in that screenshots are not pixels, are points. It means your monitor is running in retina (or hi-def) resolution, with no scaling, but with the UI being rendered at 2x.

So everything it's running fine the way it should run.

If you want to run at low-def and 3840x2160 points, select the last option at the far right.
The other options are scaled and won't be as crisp.

 

[UncleLeoTheDad]

Thanks everyone! This helps reassure that things are working as they should be.