[SOLVED] Gigabyte B550M AORUS ELITE incompatible with older PCIe 3.0 gfx card?

Oct 3, 2020
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I recently bought a Gigabyte B550M AORUS ELITE (Bios F10) board and on first install it ran fine with an older PCIe 2.0 graphics card.
Then I installed an Gigabyte GV-N660OC grapics card and the PC didn't start.
It didn't boot , no post, no beep, no lights, nothing.
It seemed completely dead, so I thought it was broken.

But then I did put in the older graphics card again and everything runs fine.
So I tried the GV-N660OC once more - nothing, not a beep.
Assuming the board was faulty, I returned it and got a replacement, but the new one displays the same odd behavior.

Naturally I then assumed that the GV-N660OC -card must be faulty and tested it in a different PC with an older Nvidia processor, but: it runs perfectly fine.

So it seems the card does not work on this specific board.
Any ideas why?

Btw. I also tried the card in the first PCIe-Slot as well as in the second slot, same behavior.
I also tested two different PSUs (one with 480W and one with 760W), no difference.
Thanks!
 
Solution
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The oddest thing is that the bord is completly dead when the card is built in, not even the led inside the power switch flashes for a millisecond or something
....
That makes it sounds like something is very basically incompatible or faulty that makes the motherboard 'sees' something it doesn't like and shut down to protect itself. Something another system doesn't react to. I would think that even if the mobo can't configure a Gen 3 card it would at least try to start up, spin fans, flash fault LED's and whatnot.

But whether it's a fault (or 'feature') in the MoBo or the GPU that makes the Mobo freak out is hard to say right now.
It sounds like you have just found the new AMD's PCIe 4.0 "feature"... Not much I would do besides contacting the motherboard's support team, they might help you with the POST part. You sure need to mention that the GPU works in another system.
There is a chance that one of the PCIe lines is bad (either in the slot or on the GPU) which in turn may cause different behavior with different controllers, but that is seldom and you need to be a tech with some tooling to be able to check and tell.
 
I recently bought a Gigabyte B550M AORUS ELITE (Bios F10) board and on first install it ran fine with an older PCIe 2.0 graphics card.
Then I installed an Gigabyte GV-N660OC grapics card and the PC didn't start.
It didn't boot , no post, no beep, no lights, nothing.
It seemed completely dead, so I thought it was broken.

But then I did put in the older graphics card again and everything runs fine.
So I tried the GV-N660OC once more - nothing, not a beep.
Assuming the board was faulty, I returned it and got a replacement, but the new one displays the same odd behavior.

Naturally I then assumed that the GV-N660OC -card must be faulty and tested it in a different PC with an older Nvidia processor, but: it runs perfectly fine.

So it seems the card does not work on this specific board.
Any ideas why?

Btw. I also tried the card in the first PCIe-Slot as well as in the second slot, same behavior.
I also tested two different PSUs (one with 480W and one with 760W), no difference.
Thanks!
Can you get into BIOS and limit PCIe support to Gen 3? You might have to do that with the older card first, then swap to the newer one.

Also, did you try the 2nd x16 slot? that one should be limited to Gen3 since it's fed by the chipset. it may also be limited to x4 lanes; which would suck for a GPU.

Even if that gets you up and running, it should work without any of this IME. But it would definitely help with decision making.
 
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Oct 3, 2020
4
0
10
Can you get into BIOS and limit PCIe support to Gen 3? You might have to do that with the older card first, then swap to the newer one.
Also, did you try the 2nd x16 slot? that one should be limited to Gen3 since it's fed by the chipset. it may also be limited to x4 lanes; which would suck for a GPU.

Thanks, but tried both already. No luck.
The oddest thing is that the bord is completly dead when the card is built in, not even the led inside the power switch flashes for a millisecond or something. As if the card creates a short circuit. But the card runs fine in another PC and the board runs fine with another card, so...
 
...
The oddest thing is that the bord is completly dead when the card is built in, not even the led inside the power switch flashes for a millisecond or something
....
That makes it sounds like something is very basically incompatible or faulty that makes the motherboard 'sees' something it doesn't like and shut down to protect itself. Something another system doesn't react to. I would think that even if the mobo can't configure a Gen 3 card it would at least try to start up, spin fans, flash fault LED's and whatnot.

But whether it's a fault (or 'feature') in the MoBo or the GPU that makes the Mobo freak out is hard to say right now.
 
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Solution