I'm using Linux for work. At home, I have Windows on my desktop, I mainly use it to play games.
One day I've tried to move to Linux for my home system, but it came out that games work slower because of DirectX adaptation layer. And most of the games can only work with DX.
I've noticed significant performance degradation in World of Warcraft and League of Legends. Used Lutrix to start them. FPS in those games visually dropped to 3-5. While on Windows there was smooth 60+ frames. I've tried that about 3 or 4 years ago.