The 3000 series chips had worse performance that 2000. You had to Crossfire them to get them to be faster.
Not true, 3870 was ~ 6-7% faster than 2900xt, plus they had a single card (3870x2, though it was still xfire) that was the fastest card available for 4 or 5 months. 2900 series was too large/hot for sandwich duty. And there was an enormous change in ideology after amd took over, forcing the development team to re-work how they designed/built their gpus. In the 6000->7000 series change they have the same group, same thought process, smaller manufacturing process, and several year's worth of positive sales momentum upon which to build. In fact, in the AT launch article and several others it was mentioned that 6970 had to be cut down b/c it was on 40 nm, thus making it reasonable for us to assume that 7970 will, at worst, be significantly more of everything. The only potential pitfall would be if 28nm is delayed for an inordinate amount of time for both NV and AMD, in which case it is entirely possible that we see iterative improvements along the lines of 4870->4890 or gtx 260->gtx 275 for the "next gen".
Really?
The 2900XT was slower than the 3870, and the the 3850 was probably faster than the 2900Pro.
http://www.anandtech.com/show/2376/7
3600 series was pretty much idendtical to the 2600 series performance wise (both were pretty poor.)
Yes, I bought a 3870 a few weeks after launch. 2 main reasons I bought that (at least over competing amd product) was that it was slightly faster than 2900xt and it was much better in the noise/heat/power dept.
Don't forget that occasionally the X1950XTX outperformed the 3870. What a beast.
Different architecture. That's like saying that "6950 occaisionally outperfroms gtx 580. What a beast".