nuc8i5bek 2 screens HMDI + USB-C

[filt3rek]

Hi, 

I have 2 screens, one connected with HDMI and another VGA through USB-C and even if I tell the 1st GPU adapter to be HDMI and second thunderbolt in the BIOS settings, in Win 10, the 1st screen is the USB-C and 2nd HDMI, the same on Debian.

I want to add that it's something OS independant because it occurs even on Boot : sometimes GRUB (the boot loader) appears on both screens, sometimes only on the VGA screen.
Then sometimes when my OS opens, it switches screens so my 1st screen is VGA and 2nd the HDMI. And sometimes the VGA screen switches also the resolutions (instead of 1280x1024 it's 1024*768 and It's the highest resolution that the parameters offer both in Win 10 and Debian)

I've the latest BIOS firmware and I set the Video params in the BIOS that 1st screen to be HDMI and 2nd Thunderbolt. Nothing to do, it does what it wants...

Can anybody help me please ?
Thanks in advance,

[David_G_Intel]

Hello filt3rek

Thank you for posting on the Intel communities. 

To confirm, the issue you experience is that the primary display rotates between the HDMI monitor and the USB-C. Is this correct?

Which USB-C to VGA adapter do you use? For the HDMI, do you use only one cable from the NUC to the display?

I will send you an e-mail to the e-mail address associated with your community profile requesting some reports that may contain sensitive information. 

Regards, 

David G 

Intel Customer Support Technician 

[filt3rek]

Hi,

Thanks for your answer.
Yes, the primary display rotates between the HDMI monitor and the USB-C.

My first display is a IIyama G-Master GE2288HS and goes on HDMI and I use only one cable HDMI yes
My second display is a Philips HNS7190T and goes through this adapter : https://www.amazon.fr/gp/product/B06XSML3GZ/
The settings in my BIOS are : IGD Primary Video Port : HDMI, IGD Secondary Video Port : Thunderbolt as you can see in the attached picture

[David_G_Intel]

Hello filt3rek

We received the information and we're investigating this request. I'll keep you updated.

Regards, 

David G 

Intel Customer Support Technician 

[David_G_Intel]

Hello filt3rek

After the investigation, we found the following:

• We always recommend using straight connections (HDMI > HDMI and USB-C > USB-C)
  • If an adapter must be used, make sure it is an active adapter
• The monitors used seem to be older models. If available, please use newer monitors for testing.
• The firmware of the monitors could be outdated, you'll have to verify with the manufacturer for firmware updates.

We did the testing from our side and we didn't get the same outcome, which means that an external component might be causing this problem.

Regards, 

David G 

Intel Customer Support Technician 

[n_scott_pearson]

FYI - An active adapter is NOT necessary when going from USB-C to DisplayPort as no conversion is taking place.

.Just saying,

...S

[filt3rek]

Hi David,

Thanks for your answer.

The 2nd monitor, this connected on the USB-C port is an old one yes, but this on HDMI is bought in 2020.
And why there are options in the NUC BIOS to specify (understand force) the order of the display (HDMI is set to be the first one and USB-C the second in my case) when it's not taken in account ? Maybe the next NUC BIOS update should have these options working ?

Best,
Michal

[David_G_Intel]

Hello filt3rek

We need you to try the previous steps to determine the cause of this behavior. Please let us know the outcome after you try them.

Regards, 

David G 

Intel Customer Support Technician 

[filt3rek]

Hi David,

I think I don't understand well...
Do you mean I have to :
-Buy another adapter, an active one, even as Scott said, it doesn't matter because there isn't any conversion
-Buy another monitors to test ???

Tell me it's a joke please, I don't believe it...

[n_scott_pearson]

No, you misread. I said no conversion was necessary for the USB-C to DisplayPort case. You aren't going to DisplayPort; you are going to VGA and the USB-C to VGA adapter is doing a conversion from digital to analog.

Is VGA the only supported input on this older monitor? A *lot* of older monitors don't work well after the signal goes through this kind of conversion. Going from USB-C to, say, DVI would be cleaner and less likely to cause problems. Alternatively, an active USB-C to HDMI adapter with a HDMI to VGA dongle would also be cleaner.

This is my opinion,

...S

[filt3rek]

Hi scott,

Thanks for your answer.

Ok I understand for the adapter. There is a DVI port on the older monitor, I'll BUY another adapter so and try like that.

But I'm sorry, these settings in the BIOS where you can "force" primary and secondary mesmerize me ...

[n_scott_pearson]

First of all, understand that, for the most part, the settings of parameters in the BIOS configuration do not get passed on to the runtime environment. Thus, even though you can force a particular monitor interface to be primary while the BIOS is using it, this doesn't necessarily mean that this monitor will be considered the primary in the Windows environment. You can hope that the Windows driver will ascertain the information from the initial hardware configuration and will follow it (unless overridden), but this cannot be guaranteed.

Clear as mud?

...S