okies, these are my 2 cents
i recall similar rumors about the R420 shortly before it tapped out, and it had no yeilds problems what so ever.
the X700 had major problems tho, they went on low transistor counts under high clocks, and it didnt worked well for them, heck it didnt worked at all. ive seen only 3 retail X700xt`s cards untill they recalled the whole thing, and brought to the X800xl/ns to the table.
yes i do think that ATi had some problems with yeilds at start, this is the first time they havent tested the water first with mid/low end cards. and tapping out a 350mil~ card on a new proccess is risky, but all the rumors from/ablout TSMC suggest that the proccess works very well, and that they will be able to supply decent yeilds.
and imo comparing the R520 to NV30 is just blasphemy, GF5800 had many problems besides the GPU(like how they tried to "solve" the memory bandwidth problem).
now about all this dellays...
IMHO ATi did had problems with yeilds which they fixed. but they turened up with much less headroom then they excpected/wanted.
ATi lost the last round, yes not a very big loss but a sufficent one, they CANNOT afford to lose again.
since ATi has much less headroom to manuver then they would have liked, they are taking a risk(dont know big is it, and ill never will
) by letting NV present thier product line first. after the G70 will be officialy out ATi can tune their cards just right so they`ll beat the G70 and allow the maximum yields as posible.
hopefully the R520 will be just what you`ll need to beat the G70, it will not blowup your minds off, and present amazing speeds and preformance.
i agree with some of the articles which say that there is no way ATi or TSMC are ready for such cards under 90nm, but ATi must take these stepps now, because the cannot afford to redesign their cards again, G70 nothing more then a pipmed NV40, a pipmed R4xx wont provide any competition nowdays. and a new design on 110 is kinda pointless imo.
im sorry for any grammar and spelling misstakes, i dont have the time to use a spell checker now.