While writing my own simple engine (on a break from Unity), I saw godot and started playing with it. So far I am a big fan of how its designed; but performance of a simple 2d scene (release build) with nothing except a single image (the default icon) and a text label (to show the framerate) is about 500 fps in the default window and 250 fps when full screened. The same thing thrown together with SFML or similar is about 1900 fps in the same size window and 950fps when full screened.
I understand the nature of a game engine, and that there is a lot more going on behind the scenes; but that is a considerable trade off. Is there anything I can do to increase performance, and close this gap somewhat?