KDE Plasma 5.27 To Provide Better Multi-Monitor Support

[Chugworth]

On an HDR capable monitor with peak brightness of at least around 1000 nits or so, the difference is pretty obvious.

Well maybe my TV is inadequate. It's a TCL 55R617, and in searching around I see mention of its brightness being 497 nits. Though it seems plenty bright for its location and I don't think I would want the overall picture any brighter.

[SilverBird775]

If your monitors support displayport passthrough (MST/multi stream transport/DP 1.4) try disabling that on all monitors if there is an option to. That fixed all the weirdness with the displays renaming themselves (and thereby confusing kde) for me with my RX 480/RX 6600 and some dells.

How curious. There is a good presentation about DisplayPort MST issues:

https://www.youtube.com/watch?v=QVlD-x_j4vU

Well, my video card is DP1.4 capable and displays are only DP1.2 capable. Sometimes I got the impression the kernel treat them as a single entity, like xdpyinfo treat the whole multihead setup as a single 7680x2160 screen. I do not like to sink deep into speculation but it seems to me the graphics card emulates the logic behind MST with the older protocol monitors. I would like to note that physical connection order matters. Display rearrangement in virtual configuration is the first option that breaks, totally useless.

[pWe00Iri3e7Z9lHOX2Qx]

I wonder if this'll mean I can finally no longer make "disable KScreen and hard-code the GPU output config in xorg.conf" one of the standard steps in my setup process.

Disabling the "KScreen 2" service and hardcoding the display config was the ultimate solution in my more complicated than average setup (triple screen with a 4 port dual display DP KVM so displays are always connecting / disconnecting). Except I do it in Xsetup. If anyone wants to do something similar, one easy way to get the xrandr output you need is to use autorandr.

For Fedora, set up your displays how you like them (position, refresh rates, etc.) in KDE's display settings. Then...

sudo dnf install autorandr
autorandr --save 3x1440p@165 # this is just a name we give to our configuration
autorandr # should show the available configurations and which one is set (detected)
autorandr --force --dry-run 3x1440p@165 | sudo tee -a /etc/sddm/Xsetup # this is what spits out the appropriate xrandr commands to append to Xsetup

OpenSUSE uses an Xsetup from a different location.

[joshx1]

The amount of hate KDE gets is staggering. Is it just mindless trolling? Caveman sees KDE, must flame..

These are opensource developers contributing their time and energy, multimonitors are an absolute pain to work with -- have you tried configuring it on systems that have billions of dollars poured into them?

[openminded]

On my side KScreen always worked quite fine, maybe because of HDMI connectors I use (never had any DP cables).

[ssokolow]

On my side KScreen always worked quite fine, maybe because of HDMI connectors I use (never had any DP cables).

I have a DVI port connected to a DVI monitor, an HDMI port connected to a DVI monitor through a passive HDMI-to-DVI cable, and a passive (i.e. just a level shifter and whatever is used to ask the card to output DVI wire protocol over the DP pins) DisplayPort++ DP-to-DVI adapter connected to a DVI monitor, and I'm the guy who said he has to disable KScreen and hard-code his display config in xorg.conf to keep things from randomly getting messed up.

[Democrab]

Reading this thread, I feel incredibly lucky because the only issue I've had with my triple screen set up and KDE is an inability to get xrandr to allow me to game in fullscreen triplehead under Linux which I don't find to be a huge deal as borderless windowed mode set to the full resolution still works fine.

[MrCooper]

Well maybe my TV is inadequate. It's a TCL 55R617, and in searching around I see mention of its brightness being 497 nits.

That's barely more than the peak brightness of SDR content, so it might indeed be hard to notice a difference on that TV.

Though it seems plenty bright for its location and I don't think I would want the overall picture any brighter.

HDR isn't about making the overall picture brighter but about making bright parts like highlights / flashes / sunlight stand out more from darker parts.

[t.s.]

The amount of hate KDE gets is staggering. Is it just mindless trolling? Caveman sees KDE, must flame..

These are opensource developers contributing their time and energy, multimonitors are an absolute pain to work with -- have you tried configuring it on systems that have billions of dollars poured into them?

It's not hate, it's facts, mind you. And they stating it not with condescending tone. Maybe you're just too attached (fanboy/girl?) of KDE Plasma? AFAIK, my experience is quite similar to them. And you know what? I still use Plasma until now. Well, considering to try another DE as there's getting worse as of late (I have to restart my laptop a few times this month because of Plasma crashing. Never ever happening before.

[degrees57]

This is good news. I'm stuck on an old version of LibreOffice (6.2) because anything newer is pretty much unsuable under multi-monitor KDE. There is a particular configuration where if LibreOffice is launched on one monitor and is never moved to the other monitor, the newer versions of LibreOffice don't break. But then I forget that the setup is so fragile, and move a window ... ugh. Easier to just downgrade to something not broken and stay there. Less than ideal.