No support for 7680x2160 240Hz on 7900XT
Brief summary of the problem:
Recently set up the new Samsung Neo G9 57" monitor, which supports a maximum of 7680x2160 @ 240Hz. No luck in getting these settings working in Linux. I confirmed on the same hardware, running a 7900XT GPU, that Windows supports the full resolution/refresh rate.
I went through a laundry list of setting tweaks to attempt to get it working, e.g. fiddling with Freesync/Displayport settings in the monitor menus, but to no avail.
I recognize we're a bit on the edge of consumer products here, but figured I throw in this report for people to see in the future and hopefully address this potential issue as these types of displays become more common.
Hardware description:
- CPU: 7900X
- GPU: 7900XT (
03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 31 [Radeon RX 7900 XT/7900 XTX] [1002:744c] (rev cc)) - System Memory: 64GB
- Display(s): 1 Samsung Neo G9 57" (
Samsung Electric Company Odyssey G95NC HNTW700417) - Type of Display Connection: DP
System information:
- Distro name and Version: Arch Linux
- Kernel version: 6.5.5
- Custom kernel: N/A
- AMD official driver version: N/A
How to reproduce the issue:
Most testing has been done under the Hyprland window manager where I first set the refresh rate under the monitor OSD settings to 240Hz and then set the monitor to 7680x2160@240 in the config file. Monitor blanks for a moment as settings are potentially changing, but ultimately returns at either 7680x2160@60 Hz, 7680x2160@120 Hz, or at 5120x1440@240. I also confirmed that the DisplayPort version on the monitor settings is set to 2.1.
I have also tested this on Plasma wayland and Plasma X11 to see if it was a window manager or wayland issue, but no dice.
Again, have confirmed that booting into Windows with the same hardware, I can successfully set the monitor to full resolution/refresh rate