SLI and Graphics Cards work on different motherboard, but not mine

[carmineg123211]

I recently bought a GeForce GTX 1080 G1 Gaming 8G Graphics card and an MSI Bridge to connect to my AORUS GeForce GTX 1080 Xtreme Edition 8G Graphics card via SLI. I connected it properly and reinstalled all the drivers on my PC, however the 'Configure SLI' option in my Nvidia control panel doesn't show up. I tested my cards and SLI bridge on a friends Motherboard and it worked. What could be causing it to not be recognized on my PC?

 

[Greeko85]

What are your system specs? Are you sure your motherboard supports sli?

 

[carmineg123211]

What are your system specs? Are you sure your motherboard supports sli?

CPU: Intel i7-7740x
Motherboard: Aorus Gaming 3 X299
Ram: 32GB Corsair Vengeance

The motherboard manual has an Nvidia SLI configuration instruction page and i have checked it on the website. It does Support SLI

 

[Greeko85]

Are both cards detected by your system? (Individually at least in device manager?)
Stupid question but they are slotted in the right pci-e slot?
After looking at your motherboards manual I saw something curious but I MUST be reading it wrong as I can't imagine its possible-its almost as if its saying cpus with 16 pci e lanes won't support sli? It has a diagram saying it will run at x8x4 making it only able to work for crossfire.

 

[carmineg123211]

Are both cards detected by your system? (Individually at least in device manager?)
Stupid question but they are slotted in the right pci-e slot?
After looking at your motherboards manual I saw something curious but I MUST be reading it wrong as I can't imagine its possible-its almost as if its saying cpus with 16 pci e lanes won't support sli? It has a diagram saying it will run at x8x4 making it only able to work for crossfire.

Yeah both the GPUs work perfectly fine. When they are both connected to the slot that the manual says they are both detected in the device manager. Ran them through the GPUZ program and they are working at optimum levels. The computer just does not show any option to enable SLI

 

[Greeko85]

When you have them in your system what pci speeds does gpu-z show? If the 2nd one comes up as x4 then thats the root of your problems.

 

[carmineg123211]

When you have them in your system what pci speeds does gpu-z show? If the 2nd one comes up as x4 then thats the root of your problems.

How did you get that that is the problem? My CPU is a 16 PCI-e lane max cpu so when the cards are connected and running in SLI, one is at x8 and the other at x4. The motherboard manual also states that this is what they will be running at, and that SLI will work if it is. So I'm not sure if that's the problem

 

[Greeko85]

SLI requires a minimum of x8 bandwidth. It seems that its a limitation of using a 16 lane cpu on a x299 platform which is designed for cpus with 28/44 lanes. I'm guessing either the board is incapable of splitting the lanes down to x8x8 or there may be a way to change it in the settings.

If you look at your manual at page 11 the 3rd table relating to using a 16 lane cpu it has a note saying 2 way configuration is available for crossfire only.

 

[carmineg123211]

SLI requires a minimum of x8 bandwidth. It seems that its a limitation of using a 16 lane cpu on a x299 platform which is designed for cpus with 28/44 lanes. I'm guessing either the board is incapable of splitting the lanes down to x8x8 or there may be a way to change it in the settings.

If you look at your manual at page 11 the 3rd table relating to using a 16 lane cpu it has a note saying 2 way configuration is available for crossfire only.

So why is it that the 2 GPUs work still even in the 8x/4x config, but the sli can't connect? Is it just the way they've made it that it is minimum 8x?

 

[Greeko85]

An Nvidia card can operate at x4 but sli just has that x8 minimum requirement. Its just the way that is designed,

 

[carmineg123211]

An Nvidia card can operate at x4 but sli just has that x8 minimum requirement. Its just the way that is designed,

AHH! You legend, thanks for that. I did some research on that and you're right.