Difference between OpenGL & DirectX?

[96th_Nightshifter]

[QUOTE=Feuerfalke;44553] You can see the effect in IL2, as under DX the textures are smoother and look more real, though the engine was optimized for OpenGL!

QUOTE]

I know nothing about either of them but I do get entirely the opposite effect here; when I use OpenGL my game looks smoother and more real?

I get better fps with DX so I use that when online and I use OpenGL for flying offline and taking screenshots etc. since as far as I know you can only use "perfect" settings under OpenGL.