240Hz refresh rate option not available

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1

Hi, as mentioned in the subject I do not have access to 240hz refresh rate.
The selection is limited to 60/120/144Hz.

Operating System: Fedora Linux 42
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0
Kernel Version: 6.14.9-300.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × 11th Gen Intel® Core™ i7-11700KF @ 3.60GHz
Memory: 62.6 GiB of RAM
Graphics Processor: AMD Radeon RX 7900 XTX
Product Name: Z590M-ITX/ax

Mesa driver version 25.0.5

The monitor is a LG OLED Ultragear 27" and supports 240Hz in Windows 11.
I have tried setting the refresh with xrandr to no avail.
Any suggestion would be really appreciated.

Screen 0: minimum 16 x 16, current 2560 x 1440, maximum 32767 x 32767
HDMI-A-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 590mm x 333mm
   2560x1440    143.87*+
   1920x1440    143.90  
   1600x1200    143.89  
   1440x1080    143.80  
   1400x1050    143.89  
   1280x1024    143.79  
   1280x960     143.86  
   1152x864     143.92  
   1024x768     143.87  
   800x600      143.83  
   640x480      143.85  
   320x240      142.05  
   1920x1200    143.89  
   1680x1050    143.88  
   1440x900     143.86  
   1280x800     143.84  
   1152x720     143.77  
   960x600      143.72  
   928x580      143.50  
   800x500      143.68  
   768x480      143.69  
   720x480      143.85  
   640x400      143.37  
   320x200      141.40  
   2048x1152    143.88  
   1920x1080    143.88  
   1600x900     143.93  
   1368x768     143.77  
   1280x720     143.67  
   1024x576     143.91  
   864x486      143.63  
   720x400      143.29  
   640x350      143.57
2

Welcome to fedora @vendest

For longer pasts please use the </> preformatet text option. I changed it for you this time.

3

Thank you, i will make sure to use the correct text option when needed during next post.

4

Are you using HDMI? If so, try DisplayPort.

5

Thanks, it worked. I never used DisplayPort ever before.
Tried the cable that came with the monitor and 240Hz refresh rate was available.

Screen 0: minimum 16 x 16, current 2560 x 1440, maximum 32767 x 32767
DP-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 590mm x 333mm
   2560x1440    239.88*+
   1920x1440    239.84  
   1600x1200    239.94  
   1440x1080    239.87  
   1400x1050    239.76  
   1280x1024    239.78  
   1280x960     239.80  
   1152x864     239.87  
   1024x768     239.74  
   800x600      239.81  
   640x480      239.72  
   320x240      238.24  
   1920x1200    239.94  
   1680x1050    239.73  
   1440x900     239.80  
   1280x800     239.70  
   1152x720     239.91  
   960x600      239.72  
   928x580      239.78  
   800x500      239.72  
   768x480      239.72  
   720x480      239.35  
   640x400      239.49  
   320x200      238.84  
   2048x1152    239.87  
   1920x1080    239.88  
   1600x900     239.72  
   1368x768     239.74  
   1280x720     239.79  
   1024x576     239.43  
   864x486      239.60  
   720x400      239.07  
   640x350      239.59
6

I believe the issue you experienced is that AMD drivers do not support HDMI 2.1 on Linux due to some legal restrictions. And HDMI 2.0 lacks the bandwidth to run the monitor at the full refresh rate, so it is limited to 144HZ.

Thankfully, DisplayPort is a more open protocol. There’s no legal restriction preventing AMD from supporting the latest versions that can handle higher bandwidths.

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