Difference btw OpenGL and DirectX

Hi all, I would like to ask is there any difference between the performance of using OpenGL and DirectX? Is that only OPenGL can work on cross-platform?

OpenGL is equivelant to the Direct3d portion of Directx. Directx has many other components that allow for music, networking, joysticks ect…

OpenGL is crossplatform, DirectX isn’t.

Performance difference is usually minimal, and generally related more to what drivers for the card are more highly optimized than the actual API. With nVidia cards, my past experience has been that OpenGL is ever so slightly faster…