[BUG] RTX 5070 Ti + Samsung G8 G81SF: 4K@240Hz mode unavailable on DisplayPort (DSC?), works on HDMI

Hello,

I’ve got a weird issue with my display and my 5070Ti and G8 G81SF on the 1.4 display port, it seems like DSC isn’t enabled ? Here’s the specifications:

nvidia-bug-report.log.gz (427.6 KB)

  • Hardware: CachyOS, Hyprland, NVIDIA 5070 Ti, Samsung Odyssey G8 G81SF.

  • Driver Version: 580.76.05

  • Problem: 4K@240Hz works perfectly in Windows. On Linux, DisplayPort is limited to 4K@120Hz. The 240Hz mode is not listed by hyprctl monitors. However, HDMI works at 4K@240Hz in Linux.

  • Troubleshooting Steps Performed:

    • nvidia_drm.modeset=1 is enabled.

    • dmesg shows no errors.

    • manually extracted EDID file via drm.edid_firmware did not solve the issue.

I can switch to HDMI, but then I face another issue of not being able to see the POST, BIOS as it seems like the default port is the first Display Port and VBios can’t be changed I guess?

I’ve searched a lot about it but didn’t find anything interresting, saw that DSC was supported so I don’t know why this isn’t working.

TY in advance