The Unigine Heaven Demo is unique in that it is the only demo which allows for the following components in one package.
The ability to compare DX9, DX10 and DX11 in the same environment allows for the unique ability to see how the different cards perform across these different comparable environments.
Both cards offer linear performance in widescreen across DX9, DX10 and DX11. The 5770 hits 30fps in DX9 at 1680x1050, and performance falls as expected in DX10 and DX11 (considering the strenuous nature of the test).
The 5700 cards can run the DX9 benchmark in Eyefinity, but it's barely more than a slideshow. The 5670 runs at just 1fps. None of the cards can run the test in Eyefinity at DX10 or DX11. These tests are strenuous on any card being sold today.
It is not possible to hit 60fps with this benchmark on a single GPU at Eyefinity resolutions. Considering it is meant to test/tax your system, that is to be expected. Here is what I was able to achieve:
Widescreen
Eyefinity