Page Flipping?!?

I have a Geforce 2 and i have run a little fullcreen benchmark under windoze D3D (page flipping), and (Hardware accelerated, under windoze and linux) OpenGL (copying data from back buffer). I got 350 fps the first time and 75 fps the second!!!
Even if in a complex game copying the most of the work is done drawing the scene, I think that page flipping (and a fullscreen context for GLX under linux, perhaps with the help of DGA), could give a good performance boost.

I can almost guarantee that your OpenGL driver is waiting for a vertical retrace, and you are running your monitor at 75 Hz, while D3D does not wait for a vertical retrace, and therefore will get much better numbers in your eyes.

Besides, how the backbuffer is shown (copy or flip or whatever method there is) is nothing OpenGL deals with.