[CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

43615 · 2022-05-22 18:59:20

My monitor (Acer XB273K GP) has a 4k@144Hz mode, which (exotically) requires two DP connections to work (since DP 1.4 doesn't have enough bandwidth). Under Windows, this worked perfectly, but Xorg treats the DPs separately and thinks that it's two monitors. I can just disable one of them or unplug one of the cables, but then I only get 120 Hz max.
GPU: Nvidia RTX 3090 FE, all software is up-to-date.
Any help would be appreciated.

Last edited by 43615 (2022-05-23 16:30:22)

seth · 2022-05-22 19:26:10

https://wiki.archlinux.org/title/Multih … al_display

43615 · 2022-05-22 19:36:25

This is just for putting them next to each other, right? That's not what I'm asking about and whatever is included in KDE already takes care of that.
I want the DPs to combine into one interface sending data to one monitor.

seth · 2022-05-22 19:37:37

Multihead#Combine_screens_into_virtual_display

43615 · 2022-05-22 20:10:09

The link wasn't broken. Maybe if you explained anything, I'd understand better. As far as I do, xrandr arranges physical monitors into virtual displays by RandR-ing on the x/y pixel plane. I want the two DP connections of my one monitor to combine together in order to enable 144 Hz mode.

seth · 2022-05-22 20:13:16

The implication wasn't that the link might be broken but to stress the topic I linked.
This is NOT about arranging outputs (side by side or otherwise) but about combining multiple outputs into a virtual one. Ie. what you want. If you don't understand that, I can't help you. If you struggle w/ something in the wiki article, ask back.
But at least maybe next time check the link first.

ngoonee · 2022-05-23 02:50:36

seth wrote:

The implication wasn't that the link might be broken but to stress the topic I linked.
This is NOT about arranging outputs (side by side or otherwise) but about combining multiple outputs into a virtual one. Ie. what you want. If you don't understand that, I can't help you. If you struggle w/ something in the wiki article, ask back.
But at least maybe next time check the link first.

Not sure if the monitor itself is splitting the monitor into two halves, or there's something exotic its doing to the signal. If the latter then there would probably need to be specific support for that monitor?

seth · 2022-05-23 05:32:18

The OP wrote:

requires two DP connections to work […] Xorg treats the DPs separately and thinks that it's two monitors

If randr sees two outputs it should™ not matter how this is organized in the HW, but we can check this

xrandr -q # w/ one and two DPs connected

Also

43615 wrote:

This is just for putting them next to each other, right? That's not what I'm asking about and whatever is included in KDE already takes care of that.
I want the DPs to combine into one interface sending data to one monitor.

1. "wrong"
2. confirms they currently operate as side-by-side multiheads
3. explicitly asks for what's answered by the linked wiki section
4. doesn't say "tried but didn't work"

Several WMs btw. allow to treat the root window as one huge monitor (for maximization etc.) - kwin used to, but that's dated information (idk whether it still does) and the more general solution is to combine the ontputs into a virtual one on the randr level.

43615 · 2022-05-23 05:36:01

Dude, chill. I was about to go to sleep and viewing it on my phone. Will try to properly mess with it later today.

seth · 2022-05-23 05:50:21

I am chill, not you "dude" and simply broke down the status quo for ngoonee.

Pro tip: next time don't jerk away wild speculations that just make you look like a fool.
This isn't some social media and you can all take the time you need before you respond.

43615 · 2022-05-23 16:29:16

xrandr --listmonitors only shows one entry. I'll just be happy with 120 Hz, the 144 mode had occasional flickering issues anyway. I know it's a rare setup and can't find any similar questions on Google, which means a lot of effort and I don't think it's worth it.
Honestly, you ruined my interest. If I really care at some point in the future, I'll just have to hope that someone more helpful answers first. Closing for now.

seth · 2022-05-23 18:23:10

You can't close the thread (you can report it for deletion or mark it as "abandoned" or so)
If you want help, start w/ "xrandr -q" for both frequencies because "xrandr --listmonitors" will only list enabled outputs.

And if xrandr would indeed only reflect one output regardless, that'd be inconsistent w/ your initial description of the problem.
(If the output is sth. like "XWAYLAND0" you're on a wayland session, not Xorg)

Also you can blame others for you deciding to quit anything as much and on as flimsy excuses as you want - it will always be your problem and nobody elses.
The very first reply is an exact solution to the originally presented problem - it's not getting more helpful than that.

Arch Linux

#1 2022-05-22 18:59:20

[CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#2 2022-05-22 19:26:10

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#3 2022-05-22 19:36:25

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#4 2022-05-22 19:37:37

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#5 2022-05-22 20:10:09

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#6 2022-05-22 20:13:16

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#7 2022-05-23 02:50:36

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#8 2022-05-23 05:32:18

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#9 2022-05-23 05:36:01

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#10 2022-05-23 05:50:21

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#11 2022-05-23 16:29:16

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

#12 2022-05-23 18:23:10

Re: [CLOSED] Xorg recognizes dual-cable monitor as two separate monitors

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