ROG Strix X570-E PCI-E lanes

[Plato]

Hi,

I built my computer last year with 2 NVME drives and a GTX 1080 Ti ( from my old PC ). I'm using 5900X as CPU.

After that recently I added a PCI-E x4 U.2-> PCI-E adapter with an Intel U.2 attached and another M.2->PCI-E adapter with a M.2 installed on it.

Now, the system sees all the drives, although my GPU is now running on PCI-E x8 mode. Is there a way to run this on PCI-E x16 mode? I know the bandwidth is enough for 1080 Ti, but I'll replace my GPU soon, and I don't want it to run on PCI-E x8..

Any advice?

[world]

Hey Plato,

Which PCIe slots are your devices connected to? On the Strix X570-E if you have 2 devices plugged into the slots with the silver edge, the connection becomes 2 8x

[Plato]

Well, as far as I see this board has 3 x16, 2 x1 connectors on it. The cards are connected like this:

• GTX 1080Ti on PCI-E x16
  
• Empty x1
  
• U.2 to PCI-E card ( x4 ) on x16
  
• Empty x1
  
• M.2 to PCI-E adapter ( x4 ) on x16
  
• 
  

So, I need to free the second x16 port, otherwise the first port becomes x4 right?

I don't think it's possible to run 2x x16 cards at x16 speed on this system if I understand correctly. Otherwise I'd try to use a x16 PCI-E NVME adapter and use a converter ( U.2 to M.2 ) for U.2 drive..

Just a quick idea but I'm not sure if this is possible.. Is it possible for using a x8 card on second or third x16 port and get x16 on first port? This will probably disable the unused x16 port completely if it works.

[world]

Unfortunately, you can't get full x16 on the first x16 port if you use an x8 card in the second x16 port. You could use the third x16 port for your drives but the 3rd x16 slot only runs at x4 speeds.

Not sure how much performance you're needing out of your m.2 drives, but you might be able to use a dual m.2 PCIe x4 card for 2 m.2 drives in the 3rd slot and still be able to use everything and get x16 on your GPU.

That said, for PCIe 4.0 x16 -> x8, you're probably looking at a ~1% reduction in performance on a 3080, so you probably won't be noticing any performance difference!