KDE and two displays with diff resolutions

[georgi7]

Greetings!

Got two monitors that I’m trying to get to work together in KDE (Leap 42.3). Main one is 4K connected to DisplayPort-0. The second one is 1080p connected to HDMI-0 and is on the right side of the main one.

When I login and use “Displays” panel and set scaling to 2 and then run

xrandr --output DisplayPort-0 --auto --output HDMI-0 --auto --panning 3840x2160+3840+0 --scale 2x2  --right-of DisplayPort-0 

It runs somewhat ok at first glance, probably the best I got it to but there are still issues like any menu of a window on the secondary display that is located far left on that screen sometimes works and sometimes doesnt which is pretty weird. Also any icon that is part of pop-up window like “save as” window is tiny, like real tiny (main display). Login screen is still tiny. When AFK for 5min and system automatically locks and show login screen, secondary display is basically split in half where right half is still showing whatever application was resting in that part of the display. Secondary display looks a bit pixelated (rough) on text and other contours.

Generally its still pretty broken and on top of that, when i try to get my xrand command executed automatically via Xsetup, after.rc, Settings->Autostart applications it doesnt even perform the same way and secondary display is split in half with only left side been usable.

I’m trying to get it to usable state without the need of manually performing command at start and preferably been also less broken than it is right now.

Thank you.

[keellambert]

Any reason that xrandr is being used?

Has the following been tried?

-systemsettings5 (System Settings)
–Display and Monitor
—Displays
----Manage and configure monitors and displays

all hw recognised configurations can be set there

[georgi7]

@keellambert

Any reason that xrandr is being used?

Has the following been tried?

-systemsettings5 (System Settings)
–Display and Monitor
—Displays
----Manage and configure monitors and displays

all hw recognised configurations can be set there

Yes.

Thats how I’m configuring the scaling (which still fails and certain icons within apps are very tiny). Also does not allow to configure the lower resolution display in a way so when i drag apps between them, transition is smooth or in other words, 1080p display is rendered as such so when placed next to the other one i can drag between them only in the upper part of the higher resolution display and hit invisible wall at the lower half. Those things are fixed when using xrandr but then there are the other issues described in the original post.

[keellambert]

can you post the output of the cmd (without any parameters)

xrandr

[georgi7]

@keellambert

can you post the output of the cmd (without any parameters)

xrandr

This is the output of “xrandr” without me executing any commands to tweak them:

Screen 0: minimum 320 x 200, current 5760 x 2160, maximum 16384 x 16384
DisplayPort-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 600mm x 340mm
   3840x2160     60.00*+  30.00  
   2560x1440     59.95  
   1920x1080     60.00    59.94  
   1600x900      60.00  
   1280x1024     60.02  
   1280x800      59.81  
   1152x864      59.97  
   1280x720      60.00    59.94  
   1024x768      60.00  
   800x600       60.32  
   720x480       60.00    59.94  
   640x480       60.00    59.94  
HDMI-0 connected 1920x1080+3840+0 (normal left inverted right x axis y axis) 531mm x 299mm
   1920x1080     60.00*+  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1600x1200     60.00  
   1680x1050     59.88  
   1280x1024     75.02    60.02  
   1440x900      74.98    59.90  
   1280x960      60.00  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
DVI-0 disconnected (normal left inverted right x axis y axis)
DVI-1 disconnected (normal left inverted right x axis y axis)

[keellambert]

What hw is in use for the graphics?

some hw allows vga+dvi, vga+hmdi but not dvi+hmdi or hmdi+hmdi

[georgi7]

@keellambert

What hw is in use for the graphics?

some hw allows vga+dvi, vga+hmdi but not dvi+hmdi or hmdi+hmdi

Radeon HD 7850 2GB

Info on 7000 series can be found here: https://www.amd.com/en-us/products/graphics/desktop/7000/7800

[keellambert]

1. If your main/motherboard has integrated graphics,
   has the graphics been disabled in the bios?

2. Have different interfaces been tried,

• Displayport - vga
  or
• Displayport - DVI
  or
• HMDI - vga … etc?

if so, are there the same issues?

3. The setup on this pc does not require the scaling factor, although the screens are of different dimensions and resolutions.
   Full screen windows can be dragged from one screen to the other and all adjustments take place automatically.
   Windows can be placed across screens also without scaling problems or distorions.

A quick look at the datasheet referenced does not indicate any limitations. Will try to find the user manual.

[keellambert]

After a quick look at the User Guide, AMD_Radeon_HD_7850_7870_enu[1][1].pdf,

the only comment is, was the previous graphics driver deleted and the pc re-booted before
installing the new card?

[georgi7]

@keellambert

1. If your main/motherboard has integrated graphics,
   has the graphics been disabled in the bios?

2. Have different interfaces been tried,

• Displayport - vga
  or
• Displayport - DVI
  or
• HMDI - vga … etc?

if so, are there the same issues?

3. The setup on this pc does not require the scaling factor, although the screens are of different dimensions and resolutions.
   Full screen windows can be dragged from one screen to the other and all adjustments take place automatically.
   Windows can be placed across screens also without scaling problems or distorions.

A quick look at the datasheet referenced does not indicate any limitations. Will try to find the user manual.

1. There is no integrated GPU
2. On this particular graphics card, only DisplayPort is capable of pulling out 4K 60 fps so using that one for the 4K display, and HDMI port (can do up to 4K 30fps) is second most modern port available to use for the other display - yes, i can try DVI and even VGA however those ports are very outdated and for the short period of time using them there can be picture distortion or artifacts
3. 4K display does “require” scaling otherwise everything is so small and I have to hug monitor to be able to use it, however when everything is scaled to be 2x bigger and then moved to the secondary display its still twice bigger, on even smaller screen and looks ridiculous; dragging between monitors can be done - yes, however when both monitors are aligned to the top side of each other, stuff can be dragged from the primary to the secondary display only when you hit that upper half of the right side of the 4K monitor where the bottom half just hit invisible wall. Now it seems Windows is doing exactly same thing when it comes to dragging between screens with different resolution and I dont know how it deals with scaling since I’m unable to test, but still that kind of dragging and scaling kind of sucks and makes the smaller display not really usable. Then comes xrandr which fix most of those issues, capable of rendering two 4K displays and scaling down the secondary output and besides the slightly more pixelized image, it makes dragging between screens useful and all app windows looking fine on either screen, but then not all icons within apps (lets say GIMP toolbox and other instances) scale properly and whats also very annoying that certain apps, located on secondary display on the left hand side are half-broken half-not when it comes to registering mouse clicks and if they still manage to get the clicks, menues just light up and still doesnt open, its just very weird

[keellambert]

Instead of adjusting scaling in xrandr, are the issues the same when done from
System Settings?

-systemssettings5
–Display and Monitor
—Displays
----Manage and Configure monitors and displays
-----Primary display (select the larger display)
------Scale Display (if not visible scroll down to the bottom of the window)

then select a scaling that you are comfortable with
then repeat with the second display

re-adjust both untill both look as required

[mrmazda]

When I use an xrandr startup script in openSUSE I put it in /etc/X11/xinit/xinitrd.d/

My inventory of xrandr usage.

[georgi7]

@keellambert

Instead of adjusting scaling in xrandr, are the issues the same when done from
System Settings?

-systemssettings5
–Display and Monitor
—Displays
----Manage and Configure monitors and displays
-----Primary display (select the larger display)
------Scale Display (if not visible scroll down to the bottom of the window)

then select a scaling that you are comfortable with
then repeat with the second display

re-adjust both untill both look as required

It doesnt look possible to adjust different scaling for different displays. Its literally one setting affecting both because it doesnt matter which display is selected.

[mrmazda]

@georgi7

It doesnt look possible to adjust different scaling for different displays. Its literally one setting affecting both because it doesnt matter which display is selected.

Correct. “ has only a single dpi specifier for the whole screen.” (for the Xorg definition of “screen”)]([opensuse-factory] Upcoming changes to HiDPI scaling in Qt - openSUSE Factory - openSUSE Mailing Lists)

[keellambert]

From previous post it looks as though X can only handle
the screen of current 5760 x 2160 at 30 Hz.

How about a compromise and try the larger display at a lower
resolution. (2560x1440 59.95)

The difference is then only 1.3:1 instead of 2:1

Does this enhance viewing?

On this pc the displays are 19201080 and 16801050 (1.1:1)
so the pixel mismatch is hardly noticeable when a window is
shared between displays.