Can I run a crossfire setup with one card in a 16x pcie slot, and the other in a 8x pcie slot?

JFo

Honorable
Jul 21, 2013
53
0
10,630
I'm looking to buy another HD 7850 and create a crossfire setup. However, to do this, I am having to buy a new motherboard that has two pcie expansion slots. I've noticed that the cheaper 970 range boards have one 16x slot and one 8x slot, compared to the more expensive 990X range boards that have two 16x slots.

I would like to save some money and go with the cheaper board, but is it possible to run two cards with one in the 16x slot and the other in the 8x slot without any sort of noticeable performance decrease?
 
Solution
Yes you can run a crossfire config with a 16x and 8x slot configuration. I use to run a 16x and 4x. Between 8x and 16x there will be no performance decrease that is even noticeable the difference between 16x and 8x is like 1-2 fps its nothing noticeable. Hope this helps!

EchoOne

Honorable
Jun 24, 2012
397
0
10,810
Yes you can run a crossfire config with a 16x and 8x slot configuration. I use to run a 16x and 4x. Between 8x and 16x there will be no performance decrease that is even noticeable the difference between 16x and 8x is like 1-2 fps its nothing noticeable. Hope this helps!
 
Solution

JFo

Honorable
Jul 21, 2013
53
0
10,630

Thanks. Much appreciated answer :)
 

JFo

Honorable
Jul 21, 2013
53
0
10,630

Actually, just one more question. The board I'm looking to buy has two x16 slots but it states that one of these slots runs at x8 bandwidth. Is this still ok?
 
That generally is the case with multi-GPU configurations for most motherboards. In that case, both your GPU's run at x8 speeds(the processor doesn't have enough lanes to allow both to run at x16 anyway).
However, at the PCI-Express 3.0 revision, this is not an issue as even x8 provides enough bandwidth for any graphics card.