When i connect this monitor using the hdmi cable to the NUC (and using the hdmi port of the display), during boot i get garbled display 60% of the time (including inside the bios).
Once windows 10 loads, all is OK though.
The problem does not reproduce when connecting the monitor to the DisplayPort port of the monitor.
The monitor maximum resolution over the HDMI 3440x1440x50hz (hdmi 1.4 is supported at max for this monitor)
To understand your question or ask.
You state that using the HDMI port results in garbled image until windows at which point its maximum is 3440x1440@50Hz. But when using the mDP to DP on the monitor everything works as intended. Is there a reason why you wouldn't want to use the DP on the panel?
My monitor DP is connected to my eGPU which isn't available at boot time . In addition in my usage scenario, it isn't always connected. So I need my monitor second port (HDMI)
So just to clarify.
You normally use your eGPU over DP to the monitor and that works fine except you don't get post information or post screen pre-windows.
If you use your HDMI you have garbled video during post but not post-windows load.
I have all the components necessary to attempt to replicate this. I'll see what I can find.
As a questioning follow-up. The ideal would be the hdmi to not be garbled, but would a stretch goal of having the TBT gpu show post information be valuable?
It's always good to have options like having my TBT in post or the bios, but do consider that most of the time I'm not gaming, so in order to save power I just use the HDMI output for work (e.g. software development), and turn off the eGPU completely.