PC Graphics

[DRDOS]

There are a lot of GPU models which a Secure Boot mode is unable to work with.
Why does this happen, what is the exact reason of this?
Is there any solution for this problem existing?

P.S.:
Several days ago i was asked by a workmate to help with this issue. So far we haven't found any solution. From about 30 of different GPU models that were tested, a Secure Boot was able to work only with 2 of them (both are of RX 500 series).
Tested with 2 motherboards, based on A520 and B550 chipsets, by Gigabyte.

[elstaci]

Sounds more like a Gigabyte BIOS or BIOS Setting such as enabling CSM Mode (legacy) or Motherboard issues or PSU Power issue.

The GPU Card should not be affected if you enable Secure Boot in BIOS. In fact during POST no drivers are loaded until Windows starts to load.

If that was the case, there would be hundreds or thousands of complaints from other Users.

You are the first User to mention that by enabling Secure Boot in BIOS with a GPU card it won't boot up.

[DRDOS]

Thanks for the reply.

Yes, i also think it could be a Gigabyte BIOS issue, most likely.
It's for sure not a Power Supply issue, as all of the tested GPU's worked properly with no Secure Boot enabled (also, the most power consuming R9 390X worked properly with Secure Boot enabled).
Also, it's not a particular motherboard hardware issue, since we tested several, each of them behaves the same way in this regard.

Now, having tested a Secure Boot mode with a lot of different GPU models, overall 'picture' has become a little bit more clear.
From HD 3000 series to HD 7000 series tested GPU's - none worked.
From R9 200/300 to RX 400/500 series - most of the tested GPU's worked (few didn't though).
We've also tested several of old NV GPU's, released in 2012 and earlier - none of them worked.
All of the tested GPU's worked properly if a Secure Boot was disabled.

So, we have the facts, but no understanding of the 'underlying system' behind of these fact, and no answer to a question - why does this happen.
Probably, this question has to be addressed to a firmware programmers.

I'll write back here later if updated information appears.

[elstaci]

So basically all the AMD GPU cards works in Legacy Mode (CSM Mode) in Gigabyte BIOS?

I would also open a AMD SUPPORT Ticket and let them know of your analysis of Gigabyte's BIOS issue. Possibly they can contact Gigabyte to see what they believe is the issue from here: https://www.amd.com/en/support/contact-email-form

GPU cards should work with BIOS in UEFI Mode unless they are old enough that they are supported only in CSM Mode. But I believe most or all RX GPU cards are made to work in UEFI Mode.

[DRDOS]

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@elstaci wrote:

So basically all the AMD GPU cards works in Legacy Mode (CSM Mode) in Gigabyte BIOS?

Yes.
Also, they all worked if within the CSM mode a UEFI mode was selected instead of Legacy mode.

The problem begins only if CSM mode is disabled and a Secure Boot mode is enabled.

One else interesting detail - there were 2 different scenarios when a Secure Boot mode was switched to a Setup state:
1. If we connect an "unsupported GPU" - POST passes and a Secure Boot mode appears to be automatically disabled, and a CSM mode automatically enabled.
2. If we connect a "supported GPU" - POST passes, a Secure Boot mode is still enabled and remains in a Setup state (a CSM mode is still disabled of course).

If a Secure Boot mode was enabled and in a User state, then with "unsupported GPU" a system is cycled in an infinite POST-fail -> Auto-Reset loop.

Probably, this issue is still infamous because there were not so many users who tried to run those quite an old GPU's in a Secure Boot mode, as it's usually necessary for Windows 11 which also requires to have a modern hardware in order to work properly.

I'll try to gather more info so that to explain the problem in a better way and with more details, and then will open a Support Ticket.

[amdman]

"From R9 200/300 to RX 400/500 series - most of the tested GPU's worked (few didn't though)"

These cards were the first ones where the manufacturers started having a Legacy and a UEFI compatible BIOS. You may be able to find and very carefully update the BIOS for the cards where they wouldn't secure boot.