How to maintain consistent resolution from login screen to desktop?

DISTRIB_RELEASE=24.04
DISTRIB_CODENAME=noble
DISTRIB_DESCRIPTION="Ubuntu 24.04.1 LTS"```


**Desktop Environment** (if applicable):
<!-- E.g., GNOME, KDE Plasma, XFCE, etc. -->
```Operating System: Kubuntu 24.04
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13
Kernel Version: 6.8.0-53250128-generic (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-7700K CPU @ 4.20GHz
Memory: 15.5 GiB of RAM
Graphics Processor: NV168```

**Problem Description**:
```The login screen is set to 3840x2160 on my 55" monitor.  
 Fonts are not readable at this resolution.  
 As soon as I log in with my password the desktop is correctly set to 1920x1080.
I have tried multiple fixes tickling the sddm config files with different 

commands randomly found after Googling, even the grub entry 

"GRUB_GFXMODE=1920x1080,auto"

Nothing seems to affect the login screen.    
I have also got a Kubuntu test installation 
using Plucky and Wayland, same thing there.```


Version
=======
KWin version: 5.27.11
Qt Version: 5.15.13
Qt compile version: 5.15.13
XCB compile version: 1.15

Operation Mode: X11 only

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_X11_XCB: yes
HAVE_EPOXY_GLX: yes

X11
===
Vendor: The X.Org Foundation
Vendor Release: 12101011
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
DAMAGE: yes; Version: 0x11
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb
XFIXES: yes; Version: 0x50
SYNC: yes; Version: 0x31
GLX: yes; Version: 0x0

Decoration
==========
Plugin: org.kde.breeze
Theme: 
Plugin recommends border size: None
onAllDesktopsAvailable: true
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
decorationButtonsLeft: 5, 3, 4
decorationButtonsRight: 6, 3, 4, 5
borderSize: 0
gridUnit: 14
font: Noto Sans,12,-1,5,50,0,0,0,0,0
smallSpacing: 3
largeSpacing: 14

Output backend
==============
Name: KWin::X11StandaloneBackend

Cursor
======
themeName: breeze_cursors
themeSize: 24

Options
=======
focusPolicy: 0
xwaylandCrashPolicy: 
xwaylandMaxCrashCount: 3
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
shadeHover: false
shadeHoverInterval: 250
separateScreenFocus: false
activeMouseScreen: true
placement: 
activationDesktopPolicy: 0
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
rollOverDesktops: true
focusStealingPreventionLevel: 1
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5015
operationMaxButtonRightClick: 5014
commandActiveTitlebar1: 0
commandActiveTitlebar2: 28
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 28
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 28
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777250
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
compositingMode: 1
useCompositing: true
hiddenPreviews: 1
glSmoothScale: 2
glStrictBinding: true
glStrictBindingFollowsDriver: true
glPreferBufferSwap: 101
glPlatformInterface: 1
windowsBlockCompositing: true
latencyPolicy: 
renderTimeEstimator: 
allowTearing: true

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
timeThreshold: 150
reActivateThreshold: 350
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Active screen follows mouse:  yes
Number of Screens: 2

Screen 0:
---------
Name: HDMI-4
Enabled: 1
Geometry: 0,0,1920x1080
Scale: 1
Refresh Rate: 60000
Adaptive Sync: incapable
Screen 1:
---------
Name: HDMI-1-2
Enabled: 1
Geometry: 1920,0,1920x1200
Scale: 1
Refresh Rate: 59950
Adaptive Sync: incapable

Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: Mesa
OpenGL renderer string: NV168
OpenGL version string: 4.3 (Compatibility Profile) Mesa 24.2.8-1ubuntu1~24.04.1
OpenGL platform interface: GLX
OpenGL shading language version string: 4.30
Driver: Unknown
GPU class: Unknown
OpenGL version: 4.3
GLSL version: 4.30
Mesa version: 24.2.8
X server version: 1.21.1
Linux kernel version: 6.8
Direct rendering: Requires strict binding: yes
GLSL shaders:  yes
Texture NPOT support:  yes
Virtual Machine:  no
OpenGL 2 Shaders are used

Loaded Effects:
---------------
colorpicker
outputlocator
screenshot
screenedge
zoom
blur
contrast
kwin4_effect_login
kwin4_effect_logout
kwin4_effect_sessionquit
slidingpopups
kwin4_effect_windowaperture
slide
kwin4_effect_morphingpopups
kwin4_effect_scale
kwin4_effect_fadingpopups
kwin4_effect_maximize
kwin4_effect_frozenapp
kwin4_effect_squash
kwin4_effect_fullscreen
kwin4_effect_dialogparent
desktopgrid
highlightwindow
overview
tileseditor
windowview
blendchanges
startupfeedback
kscreen

Currently Active Effects:
-------------------------
blur
contrast

Effect Settings:
----------------
colorpicker:

outputlocator:

screenshot:

screenedge:

zoom:
zoomFactor: 1.2
mousePointer: 0
mouseTracking: 0
focusTrackingEnabled: false
textCaretTrackingEnabled: false
focusDelay: 350
moveFactor: 20
targetZoom: 1

blur:

contrast:

kwin4_effect_login:
pluginId: kwin4_effect_login
isActiveFullScreenEffect: false

kwin4_effect_logout:
pluginId: kwin4_effect_logout
isActiveFullScreenEffect: false

kwin4_effect_sessionquit:
pluginId: kwin4_effect_sessionquit
isActiveFullScreenEffect: false

slidingpopups:
slideInDuration: 150
slideOutDuration: 250

kwin4_effect_windowaperture:
pluginId: kwin4_effect_windowaperture
isActiveFullScreenEffect: false

slide:
horizontalGap: 45
verticalGap: 20
slideBackground: true

kwin4_effect_morphingpopups:
pluginId: kwin4_effect_morphingpopups
isActiveFullScreenEffect: false

kwin4_effect_scale:
pluginId: kwin4_effect_scale
isActiveFullScreenEffect: false

kwin4_effect_fadingpopups:
pluginId: kwin4_effect_fadingpopups
isActiveFullScreenEffect: false

kwin4_effect_maximize:
pluginId: kwin4_effect_maximize
isActiveFullScreenEffect: false

kwin4_effect_frozenapp:
pluginId: kwin4_effect_frozenapp
isActiveFullScreenEffect: false

kwin4_effect_squash:
pluginId: kwin4_effect_squash
isActiveFullScreenEffect: false

kwin4_effect_fullscreen:
pluginId: kwin4_effect_fullscreen
isActiveFullScreenEffect: false

kwin4_effect_dialogparent:
pluginId: kwin4_effect_dialogparent
isActiveFullScreenEffect: false

desktopgrid:
activeView: 
gridRows: 1
gridColumns: 4
animationDuration: 300
layout: 1
partialActivationFactor: 0
gestureInProgress: false
showAddRemove: true
desktopNameAlignment: 0
desktopLayoutMode: 0
customLayoutRows: 2

highlightwindow:

overview:
activeView: 
animationDuration: 300
layout: 1
ignoreMinimized: false
blurBackground: true
partialActivationFactor: 0
gestureInProgress: false
searchText: 

tileseditor:
activeView: 
animationDuration: 200

windowview:
activeView: 
animationDuration: 300
layout: 1
ignoreMinimized: false
mode: 16723
partialActivationFactor: 0
gestureInProgress: false
searchText: 

blendchanges:

startupfeedback:
type: 3

kscreen:


Loaded Plugins:
---------------
kwin5_plugin_krunner
kwin5_plugin_nightcolor

Available Plugins:
------------------
kwin5_plugin_buttonrebinds
kwin5_plugin_colord
kwin5_plugin_krunner
kwin5_plugin_nightcolor```

My instinct tells me it is probably the EDID 
during boot that is fetched from the monitor that is 
overriding any attempts to change it.   
Any suggestions would be very welcome.

Cheers Tony

I’m not sure this could be any help or have a clue.
but did you try changing the active sync setting on the monitors to another value? they are probably set to auto… which may be the issue

Mike - That’s not such a daft idea. Never occurred to me. It’s a Samsung 55" tv QE55QN95BATXXU fed from my home theatre amplifier and computer in the loft. The amp will do a pass-through when switched off, I’ll give that a go and report back.
Thanks Tony.

Tony,
the only thing that cue me to say that was the output you provided…

the active sync status being incapable … and I thought maybe the issue resides with the actual hardware not being able to properly render… so it would be probing is my thought while trying to negotiate with the output… which would be naturally flickering
Honestly I’m stabbing in the dark on my response if that is not it I honestly don’t have a clue

Mike - There is not an awful lot of adjustment on this tv without attacking the service menu which I am loathe to do, it’s very easy to stuff the tv up in there and the ramifications with the lovely Jane if I stuff our newish £1800 telly are not worth contemplating…

Anyway I made some adjustments but no change. Sigh.

Cheers Tony

Long story short, while I managed to get the desktop resolution and UHD scaling just right, the login screen did not obey my settings, and only rendered in 4K, ergo tiny

Text above from here
https://www.dedoimedo.com/computers/plasma-hd-uhd-scaling-sddm-login-screen.html
Just offering info, hopefully, there may be a clue…?

1 Like

@tea-for-one
not my equipment but that maybe the cure

@tea-for-one
I have seen this article with my googling, doesn’t work with Noble or plucky either.

A sort of solution, I installed the proprietary Nvidia drivers and it worked.

Cheers Tony.

1 Like