the HD 5770 assumed specs are as follow.
-1120 shader processer
-gpu clock about 700mhz-750mhz
-ram speed about 800-1000mhz,
-192bit bus so think in the region of 76.8gb/s-96gb/s max bandwidth
-56 TMU's
-1gig ram (ddr5).
Honestly, I think the hd5770 might give the HD4890 a run for it's money(if not beat it) if these specs materialize.
Also, If we look at the HD5850, which uses about 151watts peak, and has 28.5% more shaders, about the same clock speeds. So I'm guessing the HD5770 will only use about 110watts (same as the HD4850)
Yeah I do know that - but there is no getting around the fact that it will be bottlenecked. 4770 on a 128 bit bus paired with gddr5 gave it around 5-10% less speed than the 4850. The gddr5 compensated impressively but at higher resolutions the bus width gave it a bottleneck.
Yep, start buying up those cheap 4870's and 4850's which are these new cards main competition. ATI will most probably cut off production on the 4870's and 4850's real soon.