   glXSwapBuffers requires 5.5ms ?!
  Having done quite some optimizations on the rendering I noticed a whoopie 5.5ms ( roughly 50% of the overall rendering cost ) to be spend in one single line of code: glXSwapBuffers. This bothers me a lot. How is it possible this swap call takes nearly as long as the rendering itself? I've got better things to do than wasting 5.5ms idling waiting for this call to finish. Is there a way I can do this call asynch so I can continue doing all the game logic calculations for the next frame ( which takes longer than 5.5ms so I would start render once this call is done for )?   
  Swapping buffers waits for all opengl calls to finish, same as glFinish(). You may also want to check if VSync is enabled as that would block to next sync.   ;  I checked already the settings. In the nVidia panel I tried with and without VSync but nothing changed. Can it be that the Linux version of the nVidia driver does block no matter if this enabled or not? If it's only a driver issue I can say "forget about it" and leave it to the player to have proper drivers. Just want to figure out if this is a problem on my end.   