So which numbers are left for Cayman and Antilles then?
Let's face it:
If based on the original 32nm-high-end-design (!), Cayman either is
(a) a 400mm2+ monster chip neither economically (yields!) nor power-wise (200W+) reasonable for an (ultra-)high-end dual-GPU-card.
(b) a shrink-design currently under development for 28nm.
In both cases, its performance should probably end up in the range of a dual-gpu card (Antilles) based on 2xBarts (= HD 69xx)
40nm Cayman in Q4 2010 would probably end up slightly slower (HD 6950?); 28nm Cayman in Q2 2011 would probably end up slightly faster (HD 6990?) than Antilles (HD 6970?).
Just my personal speculation, of course.
If those new chips actually don't have too much in common with the original 32nm designs, I'm probably all wrong.
Plus, like some of you already pointed out to me, there still is that Beta-driver indicating that Antilles = CaymanX2 ...
I guess given the current kind of rumours, you'll have to take sides in favour or against some of them - and I'm in favour of
economical reasoning (i.e. HD 6xxx series will be
heavily based on the previous 32nm designs, i.e. the "old" 32nm high-end-chip can't hit the "sweet-spot" @40nm, i.e. the "old" high-midrange chip will probably be used for a HD 6970 dual GPU card as well as the 68xx cards, i.e. any "insiliconation" of the original 32nm high-end design will, naming scheme wise, have to be placed in the 69xx territory).
Not gonna happen with a 64-bit DDR3 setup.
Why should I believe the rumoured specs of a card whose actual existence and economical feasibility I question in the first place? Seriously, if they really wanted to release another card in that price-segment using the 40nm production process, they'd be better off just taking Cedar and adding a few extra-chip goodies to rectify the 6xxx name tag ...