AMD Radeon R9 290 On Linux
Valley is Unigine's latest tech demo and also their most demanding. The NVIDIA GeForce GTX 680 was still faster than the R9 290 when using the latest binary drivers and testing from Ubuntu 13.10 with the Xfce desktop atop the i7 4770K system.
Unigine's tests are much more GPU demanding than the Source Engine with Valve's games notoriously being more CPU dependent. However, for those curious about the performance with these GPUs, here are Team Fortress 2 numbers that end up being CPU bottlenecked.
For Team Fortress 2, the GeForce GTX 680 was faster than the R9 290 and other AMD GPUs.
With Counter-Strike: Source, the R9 290 and other high-end AMD GPUs hitting a wall on the Core i7 4770K system found the performance in line with the GeForce GTX 680.