Tuan,
Your Update is misleading. If TSMC has indeed improved yields to 60% (which some sources claim), then ATI would also benefit. How would Fermi have an advantage in yield percentages over ATI? And where the hell are you getting the 4% figure from?
@turbo, that 2% figure was for a supposed "first hot lot" on GT300s, and written by some pessimist who hates Nvidia. I wouldn't pay attention to that kind of information... and the ATI yields are NOT at 4%. Find me a single link that suggests that the yields aren't in the range of 20-60%, and I'll be damn surprised. (yields SUCKED at first early Q2, but since improved to 40%. TCSM claimed yeilds were up to 60% at some investor conference, but IIRC AMD said that they were actually still at 40% shortly thereafter.)
Meanwhile, nobody said anything about 5800 yields being at 4%