AMD will soon release its new graphics circuit; Tahiti and HD 7950, 7970 that will cover the top segment in performance. The sucessoor to the HD 6800 series sporting the Barts circuit will arrive a month after HD 7950 and HD 7970.
While Tahiti sports the fresh GCN aarchitecture the remaining cards will be based on the older VLIW4 architecture that we find in the AMD HD 6900 series. Tahiti and the HD 7900 series is expected to launch in January, while the launch of HD 7800 will take another month. So instead starting at the bottom and climbing up, AMD will do the opposite.
The graphics circuit that will replace Barts is called Pitcairn and will be used by the cards HD 7870 and HD 7850. There are no clear specifications, but Pitcairn should be fairly similar to Cayman. The big upside is of course the 28nm technology that allows for a much higher transistor density, which should place Pitcairn at around 200mm².
HD 7870 and HD 7850 will according to Fudzilla cost 299 and 199 dollar respectively, which is higher than the current HD 6800 series. Both graphics cards will launch n the middle of February after the Chinese New Year, since the industry in Asia is more or less standing still during this time of year..