SDL OpenGL Performance under Windows

I tried a little OpenGL program under Windows, using WinAPI and then SDL. I
noticed (despite the WinAPI even does something more (it has music with FMOD
and a mobile camera) ) that the SDL version looks less fluid and “stable”(I
mean, visively). Why does it happen so. I configured OpenGL mode this way:

SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 8 );
SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 8 );
SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 8 );
SDL_GL_SetAttribute( SDL_GL_BUFFER_SIZE, 32 );
SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

SDL_SetVideoMode( 1024, 768, 32, SDL_OPENGL | SDL_FULLSCREEN |
SDL_DOUBLEBUF ) ;

Under WinAPI, I obviously configued similarly.–
Marco Iannaccone @Marco_Iannaccone
ICQ: 18748121 Tolkien

"What is real? How do you define real? If you’re talking about your
senses, what you feel, taste, smell, or see, then all you’re talking about
are electrical signals interpreted by your brain."
Morpheus - The Matrix