According to these pictures, the most plausible numbers go between 620-670mm^2.
And why I say so? Because hawaii is 438mm^2 and has 2816 shading units. So far we believe that fiji will have 4096 shading units which is 45,45% more than hawaii. So 438 * 1.4545 = 637mm^2 with rough translation.
1. Now here is the thing, according to rumor, GF process should make the chip denser than TSMC process. How much more denser are the GF libraries compared to TSMC? How much die space in mm would be spared on the same die on GF process compared to TSMC?
2. According to rumors also the HBM memory controller is quite a bit smaller than GDDR5 memory controller, ow much die space HBM memory controller saves from die compared to GRRD5?
3. So if the die is 620-650mm^2 and GF process is more denser and the memory controller saves space, shouldn't this mean that the chip could actually have more than 4096 shading units? Maybe the leaks has shown as only the cut down version of fiji aka fiji pro?