Question Can I do this with an 870e motherboard to free up PCIe lanes?

[boed]

Hello,

I imagine this is a newb question but unless I ask I may never learn. I'm considering the Asus ProArt X870E-CREATOR WIFI or the MSI MPG-X870E-CARBON-WIFI. I'd like to free up as many PCIe lanes as possible for the slots. First I don't know if the sata can be truly disabled on it - and if I do will it free up PCI-e lanes? I'm guessing there are a few built in things I'll never use like the sata connectors.

 

[Thunder 57]

Hello,

I imagine this is a newb question but unless I ask I may never learn. I'm considering the Asus ProArt X870E-CREATOR WIFI or the MSI MPG-X870E-CARBON-WIFI. I'd like to free up as many PCIe lanes as possible for the slots. First I don't know if the sata can be truly disabled on it - and if I do will it free up PCI-e lanes? I'm guessing there are a few built in things I'll never use like the sata connectors.

Unfortunatly no. What you see on the mobo manufacters site is what you get. I know from your post in the CPU forum you want to use a GPU and two PCIe Gen 3 x8 devices.

This is what would happen with each board:

Creator:
GPU would run at PCie Gen 4 x8, other device at PCIe Gen 3 x 8.
Last device would be limited to PCIe Gen 3 x 4.

MSI MPG:
GPU would run at PCIe Gen 5 (4 in your case) x16
First device would run at PCIe Gen 3 x4
Second device would run at PCIe Gen 3 x4

It works on how everything is connected. On paper the chipsets have all of these PCIe lanes. Mobo manufactures choose to use them on things like extra storage (m.2/SATA), USB, Wifi, etc leaving few leftover for the slots. Does that help answer your question?

The Creator may be a good option for you. The performance drop from having only x8 available to the GPU is not noticeable. TPU just tested this with the 5090 launch. The only sacrifice you would be making is running one of your x8 cards at x4.

 

[Fallen Kell]

The only other way to run the setup you want is to get more PCIe lanes by jumping to workstation class systems, using Threadripper or more preferably EPYC CPUs (as the latest threadripper is over a year old). These will provide 128 PCIe lanes, which will be enough to run multiple cards at 16x.

 

[biostud]

What would be your preferred PCIe layout?

 

[Thunder 57]

What would be your preferred PCIe layout?

He won't listen. He is unwilling to spend more for threadripper and seemingly unwilling to run an x8 card at x4.

 

[CP5670]

This is supposed to be possible on MSI by disabling USB 4, not sure about the others. 8x does actually have a negative impact in a couple of rare games.

 

[Fallen Kell]

I was thinking this over and there is another solution, get a PLX switch chip/board. Way back when there were limited PCIe lanes , some high end motherboards would include a PLX chip to multiplex the PCIe lanes and effectively get additional lanes. There were also some converters to go from a higher gen PCIe to a lower gen (i.e. turn 16x PCIe version 4.0 into 32x PCIe version 3.0)...

The only one I saw right now was a board by c-payne that will give you board with 4x PCIe 16X lanes (used for GPU coinmining farms), that you need to connect to one or two PCIe SlimSAS 8i cables (from a PCIe to SlimSAS AIC board). The SlimSAS card will run you about $175, and the c-payne board with 4x PCIe 16x will run you around $1500....

So, like I said, better to simply go to the workstation platforms.

 

[tcsenter]

The user manual should denote what connectors or slots are shared with what and the effect on them when one or another is populated.