Can I connect a 4090 to a z390 (PCIE 3.0 mobo) using a Gen 4.0 PCIE riser?

[Zberg]

As above, I think I remember hearing about blackscreens using the wrong riser cables?  

 

Would there be any issue with using the higher bandwidth 4.0 riser?  I dont want to buy it and have to send it back

 

Thanks!

[jaslion]

It was a pcie 3.0 riser on a 4.0 slot.

 

The opposite way worked fine without needing to go into the bios.

 

This was also a 3000 series issue.

 

 

[filpo]

4 minutes ago, Zberg said:

As above, I think I remember hearing about blackscreens using the wrong riser cables?  

 

Would there be any issue with using the higher bandwidth 4.0 riser?  I dont want to buy it and have to send it back

 

Thanks!

yes if you set it to gen 3 in the bios 

[RONOTHAN##]

1 minute ago, Zberg said:

Would there be any issue with using the higher bandwidth 4.0 riser?

Nope, that'll be fine. The issue with running Gen 3 risers with 4090s is when you're running them on Gen 4 motherboards, as the board doesn't detect that the riser doesn't support Gen 4 and thus tries to run at PCIe Gen 4. The solution to that situation is to manually set the PCIe mode to Gen 3. Since your board doesn't support Gen 4, it will default to Gen 3 and won't have any issues. 

 

Whether a Z390 platform will be able to fully drive a 4090 though is a different story, though. 

[Zberg]

thanks for the help from all above, very much appreciated!