MSI RTX 4090 Gaming X Trio does not run PCIe x16 (keeps running x8)

[Codehack]

1 hour ago, rijzen said:

On that board the bios setting is under settings>IO>PCIE bifurcation . not sure if that helps but its an easy thing to check

I found it. The only option it shows is x8/x8 other than Auto or Disabled, can't remember what the default setting was.

[rijzen]

54 minutes ago, Codehack said:

I found it. The only option it shows is x8/x8 other than Auto or Disabled, can't remember what the default setting was.

I think for your situation you will want bifurcation turned off. I’m not 100% but I had to do something similar on my b550 gigabyte board

[KeeriusKase]

Hi there, op. Did you ever find any solutions or did you just RMA'd your mobo? I've been having the exact same problem with my Z690 and MSI 4090 Suprim X and also Suprim Liquid X. Have gone through every single one of the troubleshooting steps listed here and elsewhere. No m.2 where it's not supposed to be, moved the card to another pci-e slot, tried the riser cable (same one I was using with my 3090 and getting gen 4 x16) and more... Still getting gen 4 x8. I have tried 4090 Gaming OC and 4090 FE and BOTH ran just fine at gen 4 x16! But that's when I switched to msi (first the air cooked one and then the aio) and now can't find another 4090 to test. Have tried the latest bios as well as beta from rog forum moderators. Also on the latest msi vbios currently. Have reset my motherboard bios also again and again. 

[Codehack]

I've fixed the problem.

 

For anyone that has the same issue, the problem in my case was the CPU. My CPU cooler was apparently overpressing it and it resulted in bad contact with some pins. I figured this is the issue after I installed a contact frame and realized the cooler was overtightened. The card is identified as PCIe Gen 4 x16 correctly.

 

 

[KeeriusKase]

8 minutes ago, Codehack said:

I've fixed the problem.

 

For anyone that has the same issue, the problem in my case was the CPU. My CPU cooler was apparently overpressing it and it resulted in bad contact with some pins. I figured this is the issue after I installed a contact frame and realized the cooler was overtightened. The card is identified as PCIe Gen 4 x16 correctly.

 

 

Thanks for the reply. I haven't messed with my CPU cooler since I installed it last year; and the trouble is I WAS getting x16 4.0 with my 3090 and later with my first 2 4090 (Gaming OC and FE. I changed nothing else other than the GPU, so I can't see how in my case at least the problem could be related to my CPU cooler. That said, at this point it can't hurt to try anything really. I don't have access to another 4090 right now and replacing the motherboard is too much work just to eliminate the mobo as a potential problem, so I might try my luck with a 3090 to see if x16 is even achievable. If not, then I'll try to RMA the motherboard as a last resort.  

[Codehack]

5 minutes ago, KeeriusKase said:

Thanks for the reply. I haven't messed with my CPU cooler since I installed it last year; and the trouble is I WAS getting x16 4.0 with my 3090 and later with my first 2 4090 (Gaming OC and FE. I changed nothing else other than the GPU, so I can't see how in my case at least the problem could be related to my CPU cooler. That said, at this point it can't hurt to try anything really. I don't have access to another 4090 right now and replacing the motherboard is too much work just to eliminate the mobo as a potential problem, so I might try my luck with a 3090 to see if x16 is even achievable. If not, then I'll try to RMA the motherboard as a last resort.  

 

Which motherboard is it?

[KeeriusKase]

19 hours ago, Codehack said:

 

Which motherboard is it?

Asus Maximus Z690 Extreme 

[dilpickle]

So I'm having the same issue where my 4090 only does 8x PCI-E 4.0. This thread is one of the top results on Google and it turns out I already made a post here trying to help OP.

 

I don't know if this was always happening but I just noticed it yesterday. The BIOS has options to set the PCI-E version and lanes and I've tried every combination there. I've tried the GPU-Z test and every other stress test I have. I've tried removing all my M.2 drives in case there was a conflict.

 

The only things I haven't tried are reseating the CPU or replacing hardware. I don't want to go thru that hassle for 1% performance gain.

 

Gigabyte Gaming OC RTX 4090

MSI Z790 Godlike