@maxiboost
It may be in this position.

Thanks but im not quite sure about that

Yes, talking to level 1 tech support usually they are often clueless and unhelpful (paid phone/email answer people often)

You must have some old early version, or they left off your switch, I see empty switch position on the end of the card, in same place where mine is Very sad to see on 580

Ohh well, switch wouldn't help your question/issue though, that is a BIOS thing that should be hidden since they didn't code it out correctly for all cards etc.

Yep they are bot at customer support, u şair that there are two bios, maybe they dont add switch i wondered if i soldered switch will it work 🤣 frankenrx

Not sure, since no switch could only be a single BIOS. You'd have to remove the fan shroud and then heatsink and show me image of the naked card.
None of that, even if you have two BIOS and add switch, will help with what you asked, so kinda a waste of time, but you can look if you want
Otherwise, you just flash what vBIOS you want to use and then you're done

i flashed the bios u send me :) but nothing changed

Yes, as I mentioned that area of BIOS is usually hidden, due to not being able to detect all card info etc.
I only updated EFI GOP, so what I sent you will only be used if you boot UEFI and disable CSM

Hi guys!

I have a card like this in my Mac Pro and I like to upgrade to latest OS. So I need to prepare the card and update it GOP to be able to see boot screens as I was told. The card is the pc version, but it's supported in MacOS mojave I use, with no boot screens.

The problem is, I'm totally new to this. Is there somewhere a guide for newbies? Some topics found here are quite advanced and my English are not helping me a lot.

Thanks you for any help in advance.