M4 mini display issues

[johnrak]

I use a M4 Mac mini with a Xiaomi A27i display. I notice that some dark colors cannot be shown properly. There are squares flashing or dancing. For example this is a picture from the background on the brew webpage.

It seems like there is an imbalance between red and green. If I try to calibrate red and green though the display’s settings this effect is disappearing from that particular color but it appears on another (for example on Finder’s window dark background).

Is this a macOS incompatibility or a display issue? Have you seen these squares again?

I enabled HDR option on the display and turned on “High Dynamic Range” in System Settings. Now it looks fine and I can also adjust the brightness using the keyboard, but the display doesn’t allow me to adjust anything. Also I notice that the default resolution is 800x600 and not 1920x1080. Is this normal?

 

[picpicmac]

I notice that the default resolution is 800x600 and not 1920x1080.

Understand that when MacOS says "resolution" it really means zoom. So 1080/600 = 1.8, or 180% zoom. This is just MacOS's way of picking a size for the display elements on the desktop and in windows, etc. You can sets the zoom ("resolution") to anything in the list (and more if you use BetterDisplay), but the results may not be aesthetically pleasing to you.

However, that MacOS thinks it's a 4:3 display (800x600) sounds to me as if there is compatibility issue.

As for color issues: are you using the HDMI cable, or a USB-C cable (for DP over USB.)

 

[johnrak]

As for color issues: are you using the HDMI cable, or a USB-C cable (for DP over USB.)

I use an HDMI cable. I tried 5 different cables without making any difference. In HDR though mode it's fine.

 

[Fishrrman]

That's a 1080p display with both HDMI and displayport in.

I'd suggest that you try a USBc (Mac end) to Displayport (display end) cable, to see if that makes a difference.

Also, try Better Display if you're not already using it.
It comes in a free version upgradeable to a paid version, but the free version works just fine for me.

Also, I'd suggest trying different refresh rates.
Try 60hz and 75hz and note differences with either one.

You might also try some different color profiles.
Use a desktop pic you like and see which profile is most pleasing.

Can you check the display's on-screen settings page, to see whether you're connected via RGB or YcBcR (I think that's what it's called)? That can make a difference, too.

 

[johnrak]

That's a 1080p display with both HDMI and displayport in.

I'd suggest that you try a USBc (Mac end) to Displayport (display end) cable, to see if that makes a difference.

Also, try Better Display if you're not already using it.
It comes in a free version upgradeable to a paid version, but the free version works just fine for me.

Also, I'd suggest trying different refresh rates.
Try 60hz and 75hz and note differences with either one.

You might also try some different color profiles.
Use a desktop pic you like and see which profile is most pleasing.

Can you check the display's on-screen settings page, to see whether you're connected via RGB or YcBcR (I think that's what it's called)? That can make a difference, too.

I tried changing all settings (including refresh rate) and only enabling HDR was able to eliminate it. I don't have a USB>Display port cable at the moment. I might get one to try that too.

 

[Mrso92]

Hello @johnrak. Have you tried connecting that monitor to some usb c hub perhaps? For the reason unknown I cannot see the hdr option when connected to my usb c hub.

Thanks

 

[Thirio2]

Have you tried a higher quality HDMI cable (8K resolution)? My M4 Mbp was unusable with a HDMI cable that worked fine with my old MacBook and 4K TV. An 8K cable cleared up all the issues. Apparently the MacBook demanded a higher quality cable. I didn’t try messing with video settings to see if that would have solved the issue.

 

[Dimvol]

This is a bad, 6-bit monitor with FRC (flickering is the result of a bad FRC). There is no HDR when the display brightness is only 250 nits. It is also unclear what is going on with the resolution. The system should offer 1920x1080 by default. I suggest returning the monitor to the seller. Replacing the cables will not help, this is not relevant in Full HD resolution.

 

[johnrak]

The issue I described in the first post is called GPU dithering in BetterDisplay and can be eliminated by disabling it in "Color Mode" menu.

I tried many different HDMI cables and a cheap USBc to Displayport and here are my findings:

- HDMI: The display turns black momentarily
- USBc-DisplayPort: The display turns on when computer Dark Wakes (doesn't show anything but I get a 10" countdown on my display until it turns off again).

HDR turned OFF on display
✅ - HiDPI working
⚠️ - need to disable GPU dithering BetterDisplay
❗️- Brightness control with 3rd party app or using display's buttons

HDR turned ON on display
✅ - no need to disable GPU dithering with 3rd party app
❗️ - HiDPI with HDMI cable working only on low resolution

HDR disabled on MacOS​

❗️- Only software brightness control​

​

HDR enabled on MacOS​

✅ - native brightness control without 3rd party app​

❌ - weird artifacts with USBc-DisplayPort cable​

So now I'm sticking with the USBc-DisplayPort cable, HDR OFF and using BetterDisplay (brightness control, disabled GPU dithering, enabled HiDPI)