TEAMSWITCHER :
Compare the pricing to nvidia 980 and 980ti...that's how the performance fits.
It's hard to tell in a lot of ways, If AMD was smart they will be outperforming the 980Ti and especially the 980. Their TDP is way higher than the 980, so all that extra power better buy a performance boost. I will be severely disappointed if R9 Fury doesn't outperform the ~$500 980 by quite a bit. But if at $550 they are at the level of the $650 980Ti, that could be interesting - even though I personally would almost certainly never buy a GPU over 200 Watts. I hope I was mistaken by comparing the TDP of the Fury to the 980.
I'm not actually anticipating much if any performance difference between Fury and Fury X aside from overclocking, as the table comparing the 300 series on the AMD website jumps from R9 Fury to R9 Fury X. They mention in the pictured slide that Fury is Dual "Fiji"... and based on the core count I suspect that what they essentially have done, is found a way to cram 2 R9 280X's onto a single die with the unified memory
.... which means performance will most likely below the R9 295X2. If that (or something similar) is the case, performance is going to be more driver dependent than normal, and it will probably underperform unless it is using DX12/Mantle. On DX11, the 4GB HBM may be split into the 2GBx2 format you expect from a Crossfire setup.
Also, there is a user guide for R9 Fury on AMD's site that describes a second card for Crossfire and how to install, but no mention of 3 or 4 cards. I don't know if this is typical or not, but it is my understanding Crossfire should support up to 4 GPUs. Maybe the limitation is that these are dual GPU cards like the 295X2.
I hope I'm wrong on that and Windows, at a Minimum, recognizes a R9 Fury as a single GPU. I thought that the Dual GPU slide was a reference to their Quantum thing, but that doesn't make sense right under the "World's fastest graphics card" tagline.