Anonymous sources from Taiwan told TechEye that AMD will not be able to launch its Radeon HD 6900 (Cayman) series in the week of November 22nd due to yield problems at TSMC. The site claims chances of hitting a Q4 2010 production/ship are slim as yields for Cayman are still in the single digits:
It doesn’t matter how big you are, however, if you don’t show up and put some skin in the game which, according to our talkative Taiwanese buddies is likely the case for AMD which simply cannot yield the product in any significant volume at manufacturer TSMC on time.
According to our sources, yields for Cayman are still in the single digits and there's minimal chance AMD will have any shot of achieving its schedule or production/ship targets for Q4. This could also really hurt if Nvidia successfully launches its GTX 580 in volume – despite its smaller RAM offering.