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jelu77

macrumors member
Original poster
Dec 1, 2020
40
13
Thailand
If so, pls list brand, model and connection type. I can’t get my Dell U2720Q to run in RGB color mode (YPbPr only) and would like to know which monitors can actually run RGB color mode with Mac Mini M1. Thx
 
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xfrgux

macrumors newbie
Dec 4, 2020
3
1
I have the same problem with my Mac Mini M1. My monitor is also U2720Q...
 

Sarpanch

macrumors regular
Jan 12, 2013
137
124
SoCal
Same problem here. I have tried different versions of the Force RGB Script but none work as M1 Macs don’t return the ioreg output in the same way as Intel Macs


data=`ioreg -l -w0 -d0 -r -c AppleDisplay`

The command above doesn’t return anything. Hopefully, someone who knows the correct syntax can create a patch that can help force RGB mode again.
 
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Gnattu

macrumors 65816
Sep 18, 2020
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The display "driver" for M1 Macs is different, and the display class name is now AppleCLCD2 instead of AppleDisplayfor AS Macs.
ioreg will not return EDID for AppleCLCD2, instead it will decode the edid to properties like the following:
Code:
"Chromaticity"={"Red"={"X"=43200,"Y"=21888},"Green"={"X"=19712,"Y"=41856},"Blue"={"X"=9792,"Y"=2816}},"DefaultWhitePoint"={"X"=20544,"Y"=21568,"Gamma"=144179}

Therefore current scripts cannot work.

But the chance is that someone can create that patch using an Intel Mac, and copy that to M1 Mac to see if it will work, if that's the case, we can obtain the edid string using something other than ioreg and manually apply the patch.
 
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xfrgux

macrumors newbie
Dec 4, 2020
3
1
The display "driver" for M1 Macs is different, and the display class name is now AppleCLCD2 instead of AppleDisplayfor AS Macs.
ioreg will not return EDID for AppleCLCD2, instead it will decode the edid to properties like the following:
Code:
"Chromaticity"={"Red"={"X"=43200,"Y"=21888},"Green"={"X"=19712,"Y"=41856},"Blue"={"X"=9792,"Y"=2816}},"DefaultWhitePoint"={"X"=20544,"Y"=21568,"Gamma"=144179}

Therefore current scripts cannot work.

But the chance is that someone can create that patch using an Intel Mac, and copy that to M1 Mac to see if it will work, if that's the case, we can obtain the edid string using something other than ioreg and manually apply the patch.
I tried to run the script on my old 2014 Macbook Pro 15 inch with DP port to the monitor and then copied the output file to M1 Mac mini. It doesn't work. It seems that the monitor can't recognize the patch file.
 
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Gnattu

macrumors 65816
Sep 18, 2020
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I tried to run the script on my old 2014 Macbook Pro 15 inch with DP port to the monitor and then copied the output file to M1 Mac mini. It doesn't work. It seems that the monitor can't recognize the patch file.
If this is the case we will need to start over for a new way could work on M1 Macs.
 

Sarpanch

macrumors regular
Jan 12, 2013
137
124
SoCal
The display "driver" for M1 Macs is different, and the display class name is now AppleCLCD2 instead of AppleDisplayfor AS Macs.
ioreg will not return EDID for AppleCLCD2, instead it will decode the edid to properties like the following:
Code:
"Chromaticity"={"Red"={"X"=43200,"Y"=21888},"Green"={"X"=19712,"Y"=41856},"Blue"={"X"=9792,"Y"=2816}},"DefaultWhitePoint"={"X"=20544,"Y"=21568,"Gamma"=144179}

Therefore current scripts cannot work.

But the chance is that someone can create that patch using an Intel Mac, and copy that to M1 Mac to see if it will work, if that's the case, we can obtain the edid string using something other than ioreg and manually apply the patch.

I copied the patch file from a 2018 Mac Mini to M1 Mini. No luck though. My Dell U2518D monitor still connects as YPbPr instead of RGB.
 

Mistercharlie

macrumors regular
Nov 27, 2020
150
60
Same here, on a Dell u3219q. iPad Pro also connects as YPbPr. But in all cases it looks great, so does it really matter? Or does RGB look better?
 
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Gnattu

macrumors 65816
Sep 18, 2020
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Same here, on a Dell u3219q. iPad Pro also connects as YPbPr. But in all cases it looks great, so does it really matter? Or does RGB look better?
In very old days YPbPr will gave a very terrible quality that you cannot even see the text clearly.
But I think that's no longer true after Mojave
 
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Gnattu

macrumors 65816
Sep 18, 2020
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I copied the patch file from a 2018 Mac Mini to M1 Mini. No luck though. My Dell U2518D monitor still connects as YPbPr instead of RGB.
copied the output file to M1
Where did you copy to? There are reports saying you have to copy to the “/Library” directory, instead of the “/System/Library” on Big Sur to make it work.
 

xfrgux

macrumors newbie
Dec 4, 2020
3
1
Where did you copy to? There are reports saying you have to copy to the “/Library” directory, instead of the “/System/Library” on Big Sur to make it work.
"/Library/Displays/Contents/Resources/Overrides"

The "System/Library" is not writable on M1 Mac even disable SIP(fail to run command "sudo mount -uw /")
 

Gnattu

macrumors 65816
Sep 18, 2020
1,107
1,671
"/Library/Displays/Contents/Resources/Overrides"

The "System/Library" is not writable on M1 Mac even disable SIP(fail to run command "sudo mount -uw /")
It is harder to make / rw, you have to disable signed system volume.
But nevermind, the patch does not work. In fact everything (like renaming the monitor) works, but the monitor will report YCbCr regardless.

The color is fine to my eyes, fonts also sharp, so I will just live with it.
 

Spindel

macrumors 6502a
Oct 5, 2020
521
655
My Asus PA27AC runs in RGB mode (as far as I can see) connected trough TB3.

It's a 1440p monitor don't know about their 4K monitors if you want the extra resolution
 

warp9

macrumors 6502
Jun 8, 2017
450
641
I have an Asus PA248QV attached to an M1 mini running in RGB mode, as well as a 65" Vizio TV in RGB mode. HDR10 does not work though and will promptly put them both into YcbCr mode, even though it's a 48Gbps cable and an HDR HDMI port.

EDIT: The 65" TV is running YcbCr after all. Blame my bad eyesight and sitting at a 10 ft distance. The Asus monitor is RGB.
 
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Sarpanch

macrumors regular
Jan 12, 2013
137
124
SoCal
Where did you copy to? There are reports saying you have to copy to the “/Library” directory, instead of the “/System/Library” on Big Sur to make it work.

Copied to /Library/Displays/Contents/Resources/Overrides

Display property correctly shows the modified name (~EDID override) but doesn’t actually enforce the RGB mode.

Hoping someone can create an updated patch with new syntax and commands for M1 Macs.
 

Aler

macrumors newbie
Nov 30, 2020
8
1
I just bought an used Benq SW270C that supports several color modes, sRGB included. AFAIK it works well with M1 Macs (USB-C, 2K resolution and 60hz refresh should be fully supported: that's not always the case, particularly with some 4k monitors). I'll keep ypu updated when I'll receive my M1 Air.
 

Gnattu

macrumors 65816
Sep 18, 2020
1,107
1,671
YcbCr mode is the $5 mode.
It was in the old days, not quite nowadays.
The Apple TV 4K has an option to switch RGB and YCbCr, and if you want to stream HDR contents, YCbCr is the only option as RGB can only be selected if you enabled either Dolby Vision or HDR.
 
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aednichols

macrumors 6502
Jun 9, 2010
383
314
It doesn't work. It seems that the monitor can't recognize the patch file.
Has anyone tried copying a file from one Intel Mac to another, instead of Intel to M1?

Maybe there is some information specific to the particular Mac that prevents it from working.

I will attempt to collect this data point tomorrow.
 

aednichols

macrumors 6502
Jun 9, 2010
383
314
Same here, on a Dell u3219q. iPad Pro also connects as YPbPr. But in all cases it looks great, so does it really matter? Or does RGB look better?
YPbPr made my U3219Q looked "wrong" in a way I couldn't put my finger on. Especially text. To the point where I was considering a return.
 

Aler

macrumors newbie
Nov 30, 2020
8
1
Benq SW270C works well with sRBG and Display P3 modes selected and color rendition is very similar to the Air display, I'm very satisfied. The only issue until now I can live with is that when I turn on the Mac from sleep sometimes the resolution on the Air display is not correct.
 

aednichols

macrumors 6502
Jun 9, 2010
383
314
Copied to /Library/Displays/Contents/Resources/Overrides

Display property correctly shows the modified name (~EDID override) but doesn’t actually enforce the RGB mode.

Hoping someone can create an updated patch with new syntax and commands for M1 Macs.
Apple should really fix this themselves; I filed feedback FB8946046 and suggest you dupe it with a description of the issue.
 
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