Gotta love these forum psychologists.
So lets see, pc per in one of their webcasts said that the fury x has essentially got parity to the 980 ti, thats a site that a lot have accused of having an nvidia bias. Going by your 2 slot system they're either trolling or delusional. Yeah...doubt it.
From the conclusion of their review:
If you asked me today which card is faster, the AMD Fury X or the GTX 980 Ti from NVIDIA, I would definitely tell you the GeForce card.
And at the end of the day, that's how you measure a graphics card.