Assuming Cayman XT is 480(X4) = 1920 Unified shaders.
Yes, that's what I have in mind.
Still, so far, the most intriguing leak/rumor/fake I've seen, is that black slide that was mentioning the RPEs.
I don't know if it holds any ground, but the idea of an RPE, that can be glued together with its brethren and create an ever stronger chip, is just great.
According to the above slide, the Cayman could be a 3 RPE part, with 480X4 shaders, 96TMUS and 48 ROPS. Now if I recall correctly, that 48ROPS does not stick well with the B3D Gurus, but I will go past that, because it gets too technical for me!
Such a part could easily be 30-50% faster than the Cypress, which is more than enough for a next gen product.
So I will stick with this theory and hope that it's somehow true. A three RPE part, could make the chip kinda rectangularish, like the GF104 though. :S
One more question that rises from all this, is what Antilles will be consisted of? Will it be a 2X 3 RPE card (2x Cayman) or 2X 2 RPE card (2x Barts)? 2x 2 RPE would make the 6990 a 4 RPE card while the Cayman a 3 RPE card, which seems only fair. The problem lies in scaling though and some games could be faster on the Cayman XT, than the Antilles XT. This could happen now as well though, when comparing the 5870 with the 5970. The difference would be greater on the 2X 2 RPE 6990 scenario though.
One last thing that has been bugging me, is the possibility of a 4 RPE part for the 6990. If the per RPE scaling is great, why the hell not? Yes the chip would be huge, but so what? It's not like they would be making millions of them, plus this part would go to an uber expensive card anyway.
The only thing I cannot fit in all that, is the memory bus. Yes I know, that's important!
All in all, this crazy secrecy on AMD's part, means one thing. They have a big ace up their sleeve and they are going for the kill. Even more so than they did with rv770 and Cypress. So even the craziest scenario, is not crazy at all.