Crossfire rx480 is the sabertooth enough

[Ieatbrains83]

Hey so I have a sabertooth 990fx r3. An Asus strix rx480 OC 8gig and a stupid Radeon xfx rx480 not OC I don't think. Also 8 gig. When i plug both in crimson says im tuning one card at 16x and the other at 8x.. I have a lot of games like shadows of war but I don't know that it's even using the sec. Card.. if it is am I really being deprived of the experience since it's on an 8x slot

 

[clutchc]

The RX-480 is not going to saturate the PCIe bus at 8 lanes. You are fine. But that board should be able to do x16, x16 if you are in the 1st 2 PCIe slots. On the other hand, if the demand isn't there, the card may only operate at 8 lanes.
Try running GPUZ's stress test. I can't remember if it tests Xfire or not.