i dont see any different scaling in benchmarks. the 4870 was 2x faster than rv670 and it had 2.5 times more shaders. i would not expect doubling the shaders to double effective performance. the problem might be the fact that there really isnt much to compare it to. might be l1 to l2 cache bandwidth.


_____________________RV770______RV870
Texture units ________40. ______80.
L1 cache bandwidth 480GB/s 1,000GB/s

L1 to L2 bandwidth 384GB/s 435GB/s