Question PCI-e only running at 4x

[Joar]

Hi,

I have a ASUS ROG STRIX Z390-F GAMING with a Nvidia RTX 3080 card.
The motherboard only have PCI-e 3.0, and the RTX card support up to PCI-e 4.0, but should it not run at 16x on the PCI-e port anyway? My card is only running at 4x

I have tried taking it out cleaning it, update BIOS, check all BIOS setting, set it to Gen3. No difference. Dont have any other things connected to PCI-e. Could the PCI-e slot be defective?

Pictures are taken while under GFX load.

Any help would be appreciated.

best regards from
Joar

 

[Order 66]

Go into BIOS and you should be able to find a setting that dictates the mode of the PCIe slots. Make sure that is set to x16. another thing that you could try is putting the GPU under load. A lot of the time GPU-Z will report the slot not running in x16 when the GPU is not under load.

 

[Joar]

Go into BIOS and you should be able to find a setting that dictates the mode of the PCIe slots. Make sure that is set to x16. another thing that you could try is putting the GPU under load. A lot of the time GPU-Z will report the slot not running in x16 when the GPU is not under load.

there is no such setting in Bios, only Gen1-3 and auto.
Like I wrote, the pictures are taken under load.

 

[bignastyid]

When the card is idle or under light load the slot will run at a lower speed, If you click the ? in gpu-z next the the bus speed it will run a render test and verify the bus speed.

 

[Order 66]

When the card is idle or under light load the slot will run at a lower speed, If you click the ? in gpu-z next the the bus speed it will run a render test and verify the bus speed.

Why does it run at a lower speed when not under load?

 

[Joar]

When the card is idle or under light load the slot will run at a lower speed, If you click the ? in gpu-z next the the bus speed it will run a render test and verify the bus speed.

Why does it run at a lower speed when not under load?

Like I said, this is under load. It does this to save power. At idle it says :

So then it runs at just one lane.

 

[Order 66]

Like I said, this is under load. It does this to save power. At idle it says :

So then it runs at just one lane.

That image is saying is using 4 lanes not 1.

 

[bignastyid]

What slot is the card installed in?

 

[Joar]

What slot is the card installed in?

Top one. Closest to the CPU. It should be the correct one.

 

[bignastyid]

Try it in the middle slot and see of it runs at 8x.

 

[Joar]

Tried that, only getting 4x there also.

 

[bignastyid]

Is there any damaged or missing pins on the card? Can you test it in another system and/or test with another card.?

 

[Joar]

Did not see any damage on the card. Dont have any other system to test it on. But I tried my old GTX 1080 card, think I got 4x on that also. Or was it 8x. Not 100% sure.

 

[SkyNetRising]

The motherboard only have PCI-e 3.0, and the RTX card support up to PCI-e 4.0, but should it not run at 16x on the PCI-e port anyway? My card is only running at 4x

Could the PCI-e slot be defective?

Clean graphics card gold contacts with eraser.

If still working only at x4 mode in top PCIE x16 slot, then problem most likely is with graphics card.
Faulty card. Board level repairs might be necessary.

Could also be bent/ broken pins in cpu socket causing this.

Here's a video with similar problem being fixed.

View: https://www.youtube.com/watch?v=q_kWonOzoag

 

[beyondlogic]

Hi,

I have a ASUS ROG STRIX Z390-F GAMING with a Nvidia RTX 3080 card.
The motherboard only have PCI-e 3.0, and the RTX card support up to PCI-e 4.0, but should it not run at 16x on the PCI-e port anyway? My card is only running at 4x

I have tried taking it out cleaning it, update BIOS, check all BIOS setting, set it to Gen3. No difference. Dont have any other things connected to PCI-e. Could the PCI-e slot be defective?

Pictures are taken while under GFX load.

Any help would be appreciated.

best regards from
Joar

if memory serves my correctly that chipset has limited bus width

it says

https://rog.asus.com/motherboards/rog-strix/rog-strix-z390-f-gaming-model/spec/

3 x PCIe 3.0/2.0 x1
2 x PCIe 3.0/2.0 x16 (x16 or dual x8)
1 x PCIe 3.0/2.0 x16 (max at x4 mode)

do you have any other cards in the pci slots.

put the card back in the top slot go into bios

in the manual

https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/ROG_STRIX_Z390-F_GAMING/E14966_ROG_STRIX_Z390-F_GAMING_BIOS_EM_WEB.pdf?model=ROG%20STRIX%20Z390-F%20GAMING

go to page 72 to select bus width of that slot then save in your bios

let me know if this fixes it

 

[Joar]

Thats one of the things that make be belive the MB is faulty. Because the card is not showing there, in bios. And I have no other cards connected to PCIe.

 

[Ralston18]

This motherboard?

User Manual (versus BIOS manual).

https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/ROG_STRIX_Z390-F_GAMING/E14842_ROG_STRIX_Z390-F_GAMING_UM_V2_WEB.pdf?model=ROG STRIX Z390-F GAMING

Double check all physical connections and configuration settings.