Oh indeed, I think even if Fermi blazes the trail and outperforms 5970 it won't have much of an impact as the chip will probably be in short supply for quite a while, probably for the whole if its initial existence as a 40nm part.
Oh yes, definately. If chip size, number per wafer and number of viable per wafer are anything to go by.
The point you make about mainstream parts is important on two fronts, one as you point out they make up most of the dollars spent on discrete graphics and therefore the profit to be earned. Second is the timing, you say Q3 new architecture (as opposed to refresh), it would be very difficult for ATi to introduce a volume product on 28nm on a completely new architecture in Q3 (when TSMC say they go into phase 5 production) even on a refresh it would be quite hard and maintain reasonable yields/costs. If Q3 is their stated goal [for a refresh] it would make sense to do 40nm at massive volumes/high yields (which are apparently available now) and wait until Q1/2 2011 for a new architecture on volume 28nm. Add in that Nvidia are probably hammering TSMC for all of their 28nm availability right now (maybe even willing to pay a lot per wafer, more than ATi at least) because the attraction of moving down to 28nm must be huge for Nv given the heat/size/cost concerns Fermi has.
Their architecuture is a good one, its giving them solid performance per watt, per mm^2. However it is an old one and it looks like Cypress is about as far as they can take it on the current design parameters. its on the high end where they need their refresh. The rest of the product range is fine/nigh untouchable at this stage. If they need to get Fusion out in 2011 on SOI, then they may be looking at getting one of their architectures primed for 32nm SOI production this year. So even if they don't come out with a new architecture this year, they'll certainly come out with a refresh on GloFo's 32nm process. GloFo is the reason why TSMC cannot simply give all their 28nm resources to Nvidia and its also why ATI won't be stuck if they do.
Given the architectural requirements the best chip for a 32nm refresh would be the HD 5870(Cypress) as on 32nm they could finally make it fit for latop production under the 59xx branding. The architectural changes needed to make the chip fit for Fusion would also prolong its life because you have to consider the changes they would have to make to the cache/register structure to enable the unit to live with higher potential memory to GPU latency and lower bandwidth, which would also scale extremely well for the desktop part as well.
It wouldn't surprise me if Nvidia's mainstream part never makes an appearance at 40nm being 28/32nm only, with reportedly poor yields at 40nm for GF100, the mainstream won't be that much better, not double anyway. So moving to 28nm and riding out the storm of little availability in Q4 whilst denying ATi 28nm for all 2010 would be a something I would pursue as Nv.
I would be surprised. They need them, so they ought to be coming. G80 based parts cannot compete with Juniper forever. They would also be pretty embarrassed to cede that much market share.
Basically, it looks like GF100 is so uneconomical right now even paying over the odds for 28nm per wafer might be cheaper for Nv per usable die and give better heat/size/cost than 40nm. While Cypress is anything but uneconomical and competing with Nv for 28nm on Nv's terms probably won't suit them, not until volume outstrips supply early in 2011 and TSMC can give lower prices.
I wouldn't count those birds until they are in the hand. Theres no reason to assume that 28nm would be perfect for them when they had trouble with 40/55nm.
Though I wouldn't advocate that ATi sit back on the success of Cypress and the apparent failure of Fermi, it looks like they can rake in a lot of dough between now and Jan 2011 and move to 28nm with a brand new architecture fully tested and ready for mass production while Nv are struggling to make 28nm work on the current architecture.
I hope so!
I don't know, just thinking out aloud...
Me too.