If that above pic is accurate, then the 6850 has 1120 SP's and the 6870 has 1280 - which to me seems plausible. I think it's also likely that the shaders going from 5 way to 4 way is a good idea, seeing as since the 2900 came out all those years ago, even though on paper, the shader clusters have an impressive throughput, the problem is actually making all of them busy. They overcomplicated things just a little too much, wasted die space in the process, and hit a practical performance wall.

Of course, right now, EVERYTHING is speculation, as there has been no kind of official release from AMD or board partners to state the actual specs, so everything has to be taken with a fairly sizeable pinch of salt.

I was looking into replacing my HD4850 with a 5770 but i'll wait til christmas, see how everything pans out.