NVIDIA/AMD OpenGL Benchmarks Of Unigine Valley
For just the Radeon HD 6770 and Radeon HD 6950 graphics cards, below are some results showing the scaling at the higher resolutions. These results are part of 1302133-FO-UNIGINEAM41 on OpenBenchmarking.org.
At 2560 x 1600, the Radeon HD 6950 GPU was only pushing out 17 FPS while the Radeon HD 6770 was down to 7 FPS. There's similar Unigine Heaven/Valley scaling results for the NVIDIA GeForce GTX 680 Kepler in this article.