Resolution and Refresh Rate Limited with T400 and LG OLED55B8PUA

I’m using endeavorOS with the nvidia driver 470.74 (the driver version that’s baked into endeavor’s installer). I’m unable to select resolutions beyond 1920x1080 - despite the display supporting resolutions up to 4096x2160 - and I’m unable to select refresh rates beyond 60fps - despite the display being capable of supporting refresh rates as high as 120fps. I’ve validated that I’m capable of driving the display with other GPUs (even as old as an AMD R5 240) at 4096x2160 as long as I turn the refresh rate down to 30fps and capable of driving the display at 120fps as long as I turn the resolution down to 1080p. Could someone help me figure out why I’m not able to achieve either of these using this card when it looks like the card should technically be able to support multiple 5K monitors?

nvidia-bug-report.log.gz (242.9 KB)

Here’s my bug report log

It seems the edid can’t be read, please try another hdmi cable.

Good call on that. Switching cables did not work, but I have got a DP to HDMI adapter in the chain that was cheap and I’d be willing to bet is limiting the bandwidth. I’ve order a new adapter to go straight from the miniDP ports to HDMI that should support 4K 60. I’ll update this thread once I’ve received the new adapter. Interesting that the old card seemed to not care about that same adapter and worked just fine though.

To drive a 4k@60 monitor and up, you should use either a real hdmi 2.0 output, or an active DP2HDMI converter.

New adapter did the trick. Took some xorg config updates, but the new adapter has got me running at the correct display characteristics now.