Question (Not your normal situation) GPU not detected in the upper PCIE (4 x16)

[Killerspoon]

My RX 470 (i have 2 of them) gaming from gigabyte are not being detected by the upper PCIE slot in the motherboard. Tried:
Resetting CMOS
Reseating GPU
Physically Inspected GPU
Physically inspected and cleaned GPU and MB slot
vBios updates

weird thing is that the pc i tested it on lets call it PC 1 is my main Pc which has a 2080 and it works perfectly in the upper slot, and i had put different gpus in there and they work perfectly too. I also tried it in my gfs PC which has a 1070 and the RX 470 doesnt work on the upper slot either so i narrowed down that the problem is in the RX 470. I have updated the bios, run bench marks while it was on the lower PCIE slot and it doesnt overheat or show any signs of anything wrong with it. Only things i can think of is a bios corruption but i feel like that means the card would have more problems. Or that the card is shorting out in the top PCIE (it is thicker than my 2080 or my gfs 1070) due to it being bigger and touching another component.
NOTES:
On PC1
Upper PCIE is a 4.0 x16,
Lower is 3.0 x4

SPECS:
PC 1
I5 12400f
2080
Msi pro b660m-a ddr4
750 PSU

gfs PC
i5 11400
Z490 (cant remember which one)
500 or 550 PSU
1070

any ideas on what it can be? Thanks very much

 

[Cyberat_88]

RX-470 is NOT PCIE 4.0 capable or rated for, only 3.0.

 

[Killerspoon]

RX-470 is NOT PCIE 4.0 capable or rated for, only 3.0.

Pcie slot in bios was in auto, and i put it in 3.0 and still didnt work.

 

[Killerspoon]

RX-470 is NOT PCIE 4.0 capable or rated for, only 3.0.

And if that was the case my evga 2080 xc is a 3.0, so why does my 2080 work fine but my rx 470 doesnt

 

[Cyberat_88]

So you're sure you're inserting the RX-470 properly in the PCIE 4.0 slot ? You mentioned you had problems with that.
Short of that I can only think that your MB has incompatibility issues with this particular series.
The 2080 is fairly new, the 470 is several steps behind and quite older.

 

[Cyberat_88]

Also, are you trying to run SLI/Crossfire ? Because most of the gaming industry has given up on it.

 

[Killerspoon]

Also, are you trying to run SLI/Crossfire ? Because most of the gaming industry has given up on it.

Not trying to sli/crossfire. What are the chances that both my msi pro b660m-a ddr4 and my gigabyte z490 gaming ac x are both not working with the rx 470, but they work with the 2080, my gfs 1070, my previous 1650. Im sure the rx470 are sitting correctly in the slot. You see what im saying is weird because then if its the mb than that means both z490 and b660 (not likely), and literally only thing i can think of is that the rx470 is shorting out since those rx470 are extra thiccccc compared to the 2080 and 1070

 

[warriorlax1234]

Did I miss something while reading through this? The 2080 works in the same MB that the RX 470 does not work in? That correct? Does the RX 470 work in your main rig? Your GF's rig?

Do you have any friends that you can have help you diagnose the card further? Such as you hooking it up in their rig? PCI Express is backwards and forwards capable. Meaning a 3.0 card will work in a 4.0 slot and vice versa. Does the rx 470 work in a bottom pci slot? Or is there only the one pci express slot? There's power to the slot right? The fan on the rx 470 spins either completely or a least jolts when power is applied? You have two RX 470's. Do they work when only 1 is used? Is the issue only when both are connected?

 

[Killerspoon]

Did I miss something while reading through this? The 2080 works in the same MB that the RX 470 does not work in? That correct? Does the RX 470 work in your main rig? Your GF's rig?

Do you have any friends that you can have help you diagnose the card further? Such as you hooking it up in their rig? PCI Express is backwards and forwards capable. Meaning a 3.0 card will work in a 4.0 slot and vice versa. Does the rx 470 work in a bottom pci slot? Or is there only the one pci express slot? There's power to the slot right? The fan on the rx 470 spins either completely or a least jolts when power is applied? You have two RX 470's. Do they work when only 1 is used? Is the issue only when both are connected?

2080 works on my rig and my gfs rig (upper pcie slot), both my rx 470s dont work on the top slot like it shows the Vga light on in the mb when its plluged into the upper slot in either rigs my gf or mine. But once i plug it into the lower slot, it works fine. Passed stressed test and everything on the bottom slots.

 

[Cyberat_88]

When did you buy the RX-470 cards and were they new ?

 

[warriorlax1234]

This is a very odd situation and a head scratcher. You've basically proven out the upper slot on the motherboard that the RX 470's are supposed to be on works since the 2080 works etc... Why does it work on the lower slot and not the upper slot? I really have no idea. If you've defaulted the bios, upgraded whatever you can, the only thing I would try, and the only option in my opinion, is to swap the motherboard. Either with the same model or a different one and see if the issue persists. See if it's a motherboard you can return. Amazon has pretty flexible return policies.

 

[Killerspoon]

Exactly, the RX 470 arent new, i got it from ebay. the thing is how weird they are acting. good thing is that x4 and x16 pcie 3.0 doesnt make a lot of difference from what i was reading. but i am bambozzled by the situation

 

[Eximo]

Only things i can think of is a bios corruption but i feel like that means the card would have more problems.

Have you checked what vBIOS are installed? They might be configured for mining and to never act as a primary display.

 

[DRagor]

Only things i can think of is a bios corruption but i feel like that means the card would have more problems.

BIOS corruption would make card behave same way on lower slot.

Or that the card is shorting out in the top PCIE (it is thicker than my 2080 or my gfs 1070) due to it being bigger and touching another component.

And it would short lower slot too in that case. Plus if that was a short the system should not start at all while you say it starts just does not recognize card.

What is most likely is either what Eximo hints or just plain mobo-GPU incompatibility. While PCIe is supposed to be compatible in both directions the reality is not so easy.

 

[Killerspoon]

SOLUTION MAYBE: stop window update from updating, safe mode, DDU the amd driver, install the RX 470 driver directly from AMD (not the autodetect) and the one that says “recommended”, it should work after that. It took me a bunch of tries and troubleshooting but i finally did it.