Ability to adjust tiled displays?

[Hphase]

deleted...

[waydabber]

Hi there - I currently don't know how to upload a custom EDID on Apple Silicon macs. Negotiation with the display is handled by the DCP which is a special part of the Apple Silicon chip (a separate system in its own right) and it has its own firmware running things and communicating with macOS. So this is different from Intel where the GPU driver had all the stuff. There might be some yet unidentified way to ask the DCP to use a custom EDID but it's not figured out yet. I'll try to investigate this further in the future though!

[waydabber]

Interesting. I don't think it's an issue with display overrides, 6144 is actually the horizontal framebuffer size limit for (entry level) M1/M2 macs for a given screen. But for M1 Pro/Max this limit should be 7680 (you said you are using a Mac Studio). Still, this number is suspicious, maybe for a tiled display this max is different? I don't think many ppl tried this besides you.

You can check what the DCP and the OS sets up as maximum sizes for the display (for example: "MaxSrcRectWidth"=7680,"MaxSrcBufferWidth"=16384,"MaxVideoSrcDownscalingWidth"=7680) under the framebuffer entry in the I/O Registry tree (which is named AppleCLCD2 for M1 systems and entry level M2).

You can get this with this command:

ioreg -r -t -c AppleCLCD2 > AppleCLCD2.txt

[DrewPro7]

I use a Mac Studio with a Barco E2 for LED Panels often. Just actually finished striking it 😅 The maximum I’ve output I’ve been able to get is 7680x1080. It has the more than enough clock headroom to go taller and wider than 7860x1080 but the max studio ignore the all custom formats go beyond it.

[DrewPro7]

Curious if it it the way MacOS is handling the Thunderbolt lanes. It does fine with Native resolutions utilizing more than one lane, but a custom resolution it only give you 1 lane of band with and expects there to be another display. Also I’m always using usbc to DP1.4 cables or usbc HDMI 2.1 cables. Do you not get tearing between heads on the dual headed dongle? I would try on a single line.

[Hphase]

Drew,
It's a tiled display. No chance for tearing. It's a single display from the mac over 2 DP's. I posted on the Barco FB page how to get it set up with the e2.

[eledtech1234]

Interesting. I don't think it's an issue with display overrides, 6144 is actually the horizontal framebuffer size limit for (entry level) M1/M2 macs for a given screen. But for M1 Pro/Max this limit should be 7680 (you said you are using a Mac Studio). Still, this number is suspicious, maybe for a tiled display this max is different? I don't think many ppl tried this besides you.

You can check what the DCP and the OS sets up as maximum sizes for the display (for example: "MaxSrcRectWidth"=7680,"MaxSrcBufferWidth"=16384,"MaxVideoSrcDownscalingWidth"=7680) under the framebuffer entry in the I/O Registry tree (which is named AppleCLCD2 for M1 systems and entry level M2).

You can get this with this command:

ioreg -r -t -c AppleCLCD2 > AppleCLCD2.txt

I check this on my M1Max with Ventura OS.
it shows me max 7680.
but as soon i do resolutions over 6144 doesnt work (fall back to 1920x1080)
in Monterey its working, as we spoke in other thread.

[waydabber]

Note: with the latest app version now you can override the EDID of a display on Apple Silicon if that is any help.

[waydabber]

Let's reference the other related thread here as well where there is some practical info on how to set up tiled displays:

#713 (reply in thread)

[waydabber]

Hmm. I thought we are talking about EDID tiles, not arranging independent displays next to each other in macOS. :)

[waydabber]

I was just pointing out that the ChatGPT generated code simply uses public macOS APIs to arrange two screens next to each other, the same way you can do it in System Settings (or of course with BetterDisplay as well even using CLI).

[ectoplasmosis]

I don't understand the utility of these mostly-gibberish ChatGPT outputs; tiled displays are defined by EDIDs, as @waydabber already mentioned.

What exactly are you looking for in these AI-generated outputs?

[waydabber]

All this is talking about how macOS display management simply works by default (each display is located in one contiguous global coordinate system). Later macOS versions introduced the ability to have each displays separate spaces but if you disable it, the system will revert to the original state, where you can simply move windows and objects among adjacent display boundaries. All this has nothing to do at all with the EDID defined tiled display topology I am afraid (as @ectoplasmosis rightly pointed out).

[Hphase]

No worries, I'll move on. I do know that a mosaic tiled display topology can be created without loading EDID's. The part you are missing is how to take 2 outputs and create a single display. if it was EDID related then why can't you load the 2 EDIDS in better display to create a single display?