I previously posted to Lemmy about my 8K TV and attempts to get it working on Linux. Based on suggestions there I bought an Intel Arc B580 which apparently supports 8K. But I can’t get that on my TV. I’ve tried multiple cables, multiple video cards (including the NVidia one), and both HDMI and DisplayPort output from GPUs.

How can I find out where the problem is? Can I interrogate a HDMI or DisplayPort target to find out what modes it claims to support? Can I ask the GPU what modes are actually supported on it’s outputs? If so how?