On the linkedIn account from an ex-AMD employee there is a reference of a dGPU (Dedicated graphics card) tagged under codename F. The reference refers towards a GPU fabbed at GlobalFoundries and Sams... AMD Polaris Project F GPU Surfaces
Well, I would say something bit different: AMD vs nV on 28nm. AMD always used bit higher density than nVidia. At cost of bit bigger leakage and lower clocks. Fiji (Fury X) has 8.9B transistors in area of 596mm^2. As can be seen here, 14nm LPP takes is 3.55times smaller area than same block made on 28nm HPP. But let's say AMD had it too dense last round around and this time they'll have lower density for improved power efficiency. And same amount of transistors will not fit 3.55 times smaller area, but will need more spare (2.5 times smaller only). This "project F is a 232 mm^2" would have around "232 / 596 * 2.5 = 0.97" times as many transistors as Fiji. In other words, this is next Fiji!