24-Way AMD Radeon vs. NVIDIA GeForce Linux Graphics Card Comparison
NVIDIA's high-end Kepler graphics cards continue to shine great on Linux with Unigine Valley.
Unvanquished is one of the most promising open-source games at the moment. Any mid-range graphics card on the respective proprietary graphics driver can easily be pushing out more than 60 FPS at 2560 x 1600.