No display during boot on HDMI..

[gijoe79]

So I've been experiencing this problem for a long time now, over multiple monitors, and hardware, with the GPU being the only thing that remained the same.

My current hardware is:
GPU: KFA2 RTX3080 12GB
CPU: Ryzen 9 7900x
Mobo: X670e Aorus Master
Monitor: Samsung Neo G7

(I had exactly the same problem with my AM4 hardware and a different 4k monitor)

Basically when I boot the PC using the HDMI port on the GPU, I get no display until the PC gets to the Desktop. And I'm pretty sure it's related to the HDMI port on the GPU because I can get a display with DP, and with the iGPU HDMI port on the motherboard.
It's only the HDMI port on the GPU where I get no display.

However I can get a display if I go into the bios and switch on compatibility support (CSM).
I suppose CSM is a solution, but I don't think it addresses the actual problem, and I'm leaning towards it being a resolution issue with the KFA2 bios on the GPU, but I could be wrong. I've seen other people with the same problem with AMD GPUs, with lesser known manufacturers such as ASROCK, and I'm thinking that perhaps these manufacturers don't account for bios resolutions/UEFI/legacy in the firmware, and my thinking is that some monitors are not able to display whatever strange resolutions the GPU (HDMI) is sending them.
Does this make sense?

I thought I'd ask here since it seems to be one of the few places where people might know about GPU firmware/bios and if this might be the issue.
I have tried flashing another compatible GPU bios from I think it was fron an INNO3D 12GB 3080, but it didn't make a difference. And from what I understand we can't edit the GPU bios on newer cards.

And I've tried bcdedit /set highestmode on but it didn't help either.

Does anybody have any ideas where to go from here? Could it be related to the GPU bios, or something else?

 

[eidairaman1]

Turn off fast boot, contact KFA for a gpu bios

 

[Caring1]

Try another quality HDMI cable.

 

[gijoe79]

Turn off fast boot, contact KFA for a gpu bios

Try another quality HDMI cable.

Yea, I've tried these.. waiting on KFA to get back to me..

 

[Sarajiel]

CPU: Ryzen 9 7900x
Mobo: X670e Aorus Master

You could try disabling your iGPU and/or manually try setting your primary GPU during boot.
Not sure if it's related to your problem, but I've noticed that Gigabyte AM5 boards sometimes assign the output to the wrong GPU on their initial boot after reset or cold start.

 

[gijoe79]

You could try disabling your iGPU and/or manually try setting your primary GPU during boot.
Not sure if it's related to your problem, but I've noticed that Gigabyte AM5 boards sometimes assign the output to the wrong GPU on their initial boot after reset or cold start.

Yea, I've tried those too, on the ASUS x570, and the x670e.
But I think the correct display is definitely being used alright because it works with CSM enabled, and also the monitor wakes up for a second a few times during boot, (backlight comes on) but then goes off again and the monitor says no display detected.