Digital Cinema 4K Resolution on MacBook Pro M1 Max

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Digital Cinema 4K Resolution on MacBook Pro M1 Max

I am using LG 31MU97Z-B monitor which offers me 4096x2160@24 using HDMI 2.0 port on my macbook but when I am using USB-C to DisplayPort cable it recognize monitor and display in 3840x2160@60 and I cannot change it in System Settings to use full resolution 4096x2160@60

According to monitor specs available in below url

https://www.lg.com/us/business/download/resources/BT00001837/BT00001837_1931.pdf

monitor is able to display 4096x2160@60 and I was able to do it using PC with nVidia graphic card and display port cable.

Issue is with macBook that somehow does not recognize monitor properly through displayPort connection.

Please tell me if I can get any updates or software that can help me use full capacity of display with my MacBook Pro M1 Max 64GB and 24 cores GPU.

I am using Monterey 12.2.1 (21D62) and no updates available now.

MacBook Pro 16″, macOS 12.2

Posted on Mar 6, 2022 11:07 AM

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Answer 1

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lovelyshot Author

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Mar 6, 2022 1:02 PM in response to lovelyshot

OK I figure out using SwitchResX

2048 x 1080 HiDPi selected in Current Resolutions of SwitchResX.

The image is now going to my monitor at 4096x2160 with the HUD scale of 2048 x 1080.

31MU97:

Resolution: 4096x2160 (DCI/Cinema 4K)

UI Looks like: 2048 x 1080 @ 60.00Hz

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Answer 2

lovelyshot Author

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Mar 6, 2022 11:17 AM in response to Grant Bennet-Alder

I know it well what you described and I am sorry that my question put you into confusion so you replied in that way I will try to be more succinct now.

My concern is about real resolution and currently I have 2 black stripes on sides (left & right) displayed on my screen because monitor is design to display max 4096x2160@60 but macBook allowed me to display only 3840x2160@60 which causing 2 black stripes on sides :(

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Answer 3

lovelyshot Author

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Mar 6, 2022 12:51 PM in response to Grant Bennet-Alder

I cannot see any settings in my display that will allow to use HDMI 2.0. Maximum suported is 1.4 and display port is 1.2 and for display port I can see Enable/Disable value for option "DisplayPort 1.2" tried both when connected through displayport. Nothing happened.

SwitchResX is straightforward and works with

Resolution: 4096x2160 (DCI/Cinema 4K)

UI Looks like: 4096 x 2160 @ 60.00Hz

although I am not sure how setup scaling for macOS UI.

I connected both HDMI cable and DisplayPort and definitely somehow display "reports" to MacBook that display port capability is only this 3840x2160@60

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Answer 4

Mar 6, 2022 11:09 AM in response to lovelyshot

HDMI cables you want for HDMI-only Monitors (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:

"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--

"Ultra High Speed HDMI cable" or that + "48G"

Cables with No Certification tags are good for your standard 720p TV set, and not much more.

HDMI computer output is bandwidth limited. HDMI output is suitable only for DIRECT connection to a display's HDMI input, PROVIDED you use a Premium High Speed cable with a certification tag.

it can NOT be converted to another interface using ordinary, inexpensive adapters, and if you did actually manage get it adapted to something else, the supported resolutions and refresh rates would be pitiful.

Use DisplayPort family or its support built into ThunderBolt or USB-C.

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Answer 5

Mar 6, 2022 11:10 AM in response to lovelyshot

Displays Preferences shows SCALED resolutions. These are NOT the Hardware resolutions you display is set to. These are effective resolutions for TEXT when displayed on that display when you select Scaled.

They are intended to be a convenience for you, but they often cause concern and outright alarm instead.

To see the ACTUAL resolution your display is set to use:

 Menu > about this Mac > (system report) > Graphics & Displays

Select your display and scroll around until you see two items.

The first is self explanatory: 'Resolution:' 2560 by 1080

This is the hardware resolution at which your display is operating. Graphics are drawn at this Actual Resolution. But there is a problem -- If text were displayed at the Actual Resolution, it would be microscopic and unreadable.

The second resolution shown is 'User Interface Looks like:' this reveals the apparent size of text displayed on your display after scaling is applied ONLY to textual items.

Text is rendered at full resolution, then SCALED by the display Hardware by a factor (like 1.2 or 1.5, or 2.0) before it is aded to the display buffer. This makes it fully readable, yet maintains crisp edges that would be lost otherwise.

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Answer 6

Mar 6, 2022 11:19 AM in response to lovelyshot

Because the Mac queries the display, asking "what is your name and what are your capabilities" we often get surprising results that are more or less resolution than expected.

This can happen when the your display's on-screen controls (set in the display itself, Not on the Mac) are set to HDMI 1.4, which does not support as high a resolution as HDMI 2.0

in general a PC does not ask the display about its capabilities, it just manually sets the resolution you said and lets it rip.

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Answer 7

Mar 6, 2022 11:28 AM in response to lovelyshot

In the specific case I mentioned, you change on-screen display settings (in the display) to tell the display to use HDMI 2.0, rather than the default HDMI 1.4.

when the Mac asks the display about its capabilities, it will report the updated capabilities.

if you want to dive deep into the gory details, you can use a Utility like SwitchResX to examine (and potentially modify) what is being promised.

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Answer 8

lovelyshot Author

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5 points

Mar 6, 2022 4:07 PM in response to Grant Bennet-Alder

I am not using HDMI to DisplayPort adapter. I am using USB-C to DisplayPort and after setting resolution manually via SwitchResX everything is as it should be.

Cable quality does not matter in this particular case.

HDMI for this LG display has limitation to 24 frames per second and this is LG display feature not related to cable.

I am not interested in using hdmi port due to that reason otherwise I will be happy to have one more usb-c port free for other purposes.

I hope now situation is clear. Solution is to use external software(SwitchResX) because of the weird MacOS behaviour - for me these options should be included in OS UI.

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