Just for those electrical engineers and signal engineers out there, a genuine question that needs testing:
We know that USB DACs can be affected by a ground loop, but what is the effect of a ground loop on a HDMI 2.0 signal? Would it go from stable signal, to no signal?
If anyone with TMDS testing equipment can verify, we can then know that ground loops can significantly affect HDMI 2.0 signals.
I don’t know about signal stability but I had a ground loop from a HDMI cable which caused audible (quite loud actually) noise from two recievers (the one the hdmi was connected to and another which was connected to the first).
But I’m not sure if digital signals would care about low frequency noise like a ground loop
I’m asking because VFIO setups where the host and guest GPUs connect to the same monitor could have this issue at 4K 60hz. Don’t assume low frequency noise won’t affect higher frequency clock generators. It may actually affect it to cause signal loss.
I want to see if there’s a measurable difference in this scenario with TMDS measuring oscilloscopes.
If ground loops aren’t the issue, it’s an issue with display drivers freaking out with 2 4K 60p displays outputting at the same time (which is not uncommon for Xorg to screw up)