Now imagine what happens, when NVIDIA starts optimizing their Linux drivers for certain games like they do on Windows. They managed to get out +50% more performance in Metro:LL with the latest Windows driver that was just released a few days ago.
Performance Boost – Increases performance by up to 50% for GeForce 400/500/600/700 series GPUs in several PC games vs. GeForce 331.65 WHQL-certified drivers. Results will vary depending on your GPU and system configuration. Here is one example of measured gains:
GeForce GTX 770/780/TITAN/780Ti:
Up to 50% in Metro: Last Light
Up to 26% in Crysis 3
Up to 18% in Battlefield 4