AMD brags about the Mantle API support for Sid Meier's Civilization: Beyond Earth in their just-released beta Catalyst drivers, touting a 0.5 FPS advantage running the strategy game at 3840x2160 on a Radeon R9 290X 8GB accelerator compared to a GeForce GTX 980, claiming this minute advantage places them "over a year ahead of other graphics companies in delivering high-throughput, high-efficiency graphics to gamers and developers." Here's the justification for that claim:

In Sid Meier's Civilization®: Beyond Earth™ internal benchmark test at 3840x2160, the AMD Radeon™ R9 290X 8GB with Mantle outperforms the GeForce GTX 980 with DirectX® 11, NVIDIA's highest-performing single-GPU graphics card as of October 20, 2014, by 45.38 average FPS to 44.89 average FPS using the Ultra in-game preset with 8xAA. Test system: Intel Core i7-4960X, 16GB DDR3-1866, Asus SABERTOOTH X79, Windows 8.1 x64, AMD Catalyst™ 14.9.2 Beta and ForceWare 344.16 WHQL.