[SOLVED] GPU only running at 4x

[Vrealon]

I have a 1080Ti on a Z390 board's top slot with the others empty and it's only running at 4x according to HWiNFO and GPU-Z. I ran the stresser to check if it was in a power save mode but nothing has made it leave 4x mode. I believe this started after I installed an M.2 NVME drive. But why would this happen? I thought the chipset handled M.2 ports leaving 16x for PCIE slots? I game at 4K so this bandwidth problem is alot more severe for me. I can't remove the drive because it's my OS drive and I'm not going to go back to the early SATA SSD that I came from. Could anyone help me figure this out?

 

[Phaaze88]

What is your cpu and Z390 motherboard model?
Does the motherboard manual mention anything about bandwidth sharing?

Go into bios - maybe the Advanced Settings(depends on mobo make and model)?
PCH Configuration - You should be able to manually set the pcie speed to Gen3?

 

[Vrealon]

https://ca.pcpartpicker.com/user/Vraelon/saved/zcvCLk
Its Gen3

 

[Phaaze88]

Go into bios > Advanced tab > PCH Configuration > PCI Express Config. Are you able to manually set the link speed to Gen3?

The next thing would be to take the cpu out and check for bent/broken pins in the motherboard socket, because I only found one thing regarding bandwidth limitations with the storage when using M.2, and it's not related to the first PCIE slot:
Sata6G_2 get disabled when an M.2 is installed in M.2_1.

 

[Vrealon]

The SATA restriction only applies with SATA M.2 SSDs. Not NVME SSDs.

Also, here is the GPU-Z screenshot:

It says its running "@ x4 3.0"

 

[Phaaze88]

Still in x4 even with render test running...
Have you already tried the gpu in the other 2 slots?
Do you have another gpu to test with?

 

[Vrealon]

Thing is, it was running at 16x when I built it (Pre-NVME SSD) and I installed the SSD recently. I think it is the SSD because it's the only hardware change I've made before this problem. But I just cant imagine how it would be the problem. The SSD is PCIe 4.0 (for forwards compatibility) and I'm running it in 3.0 (Z390) could this have something to do with it?

 

[Phaaze88]

Monitor your gpu's core and memory clock speeds on Gpu-Z Sensors tab while in game, or using the render test.

The motherboard doesn't even support PCIE 4.0...
I suspect a driver conflict.

 

[Vrealon]

I know it doesn't support 4.0, I bought it because my next build will. It functions fine at 3.0, it just doesn't read full 5GB/s speed.

 

[Vrealon]

FOUND THE SOLUTION! Disabling PCIe multi device aggregation fixed it. It is for using multiple PCIe devices in a single slot (those 16x to 4*4x M.2 boards). The setting was called "Hyper M.2X16" under Advanced\Onboard Devices Configuration. I don't know how it managed to turn itself on, maybe my PCIe 4.0 SSD made it think there were multiple PCIe 3.0 SSDs.

I assume the setting's name comes from https://www.asus.com/ca-en/Motherboard-Accessories/HYPER-M-2-X16-CARD-V2/

 

[Phaaze88]

Oh.
That's an option for setting up Intel RAID. You must've turned it on by mistake.