wow... thats dissapointing...
6000 is 10% more efficient/sp/clock and only has 320sps more... which is a mere 17% more than 5000...

so at the same clocks (and i doubt itll come clocked notably higher) 6970 will only be 27% faster than a 5870... and thats an UP TO... if geometry is limiting it will be more, but... when is that actually the case besides tessellation benchmarks?

6970 is definitely slower than the 580 then...
not much, but 5-10% on average i guess...