It is not about performance/throughput. There are various factors at play: first of all, the synchronization is basically waiting for the monitor to finish disp

It is not about performance/throughput. There are various factors at play: first of all, the synchronization is basically waiting for the monitor to finish displaying the last image before you send the new one. Second, unless the application takes over the screen (e.g. fullscreen games), the applications do not run in sync with the window system (and you do not want that because you do not want a single application to cause problems for other applications like hogging the screen updates). When you combine these two there is nothing really the application can do. As you wrote: > I suppose the challenge is composting stuff from different processes every frame. This is a significant part of the issue, though the fact that synchronization essentially means waiting is also another one (without synchronizing you get partial frames but those partial frames are still feedback for the user that makes the desktop feel more responsive).