You are thinking short sighted.
If barts is named the 6870, the pricing of it has to be 259 most likely 299. No damn way will they allow the 6870 to be priced under 200 dollars. What does that do to cayman pro and cayman xt and why the name change to 69xx? It is to justify a higher price. Cayman will start at 399(it a substantially bigger chip and xt will probably hit 499-550. The naming scheme is all being changed to allow higher chip pricing.
If a 5770 was 1/4 the price of a 5970 and a 5870 was .66 the cost of a 5970. Look what it does to the pricing of antilles. Welcome to the 800 dollar graphics card.
Its really scary for the consumer because honestly, it been a while since such small chips(die size) were so expensive. Last time it happened, AMD and NV were doing some price fixing. Atleast with fermi, you know they have to sell it for so much because it is such a expensive chip to make because of size and yields. This could be really bad for the consumer as Nvidia takes a hit. In a worse case scenario, until Nvida responds, we have NV selling below cost to be competitive vs AMD raping us on chips, ala Athlon x2 vs core2 duo days.
Bookmarks