[SDL] SDL slower in fullscreen mode

[Jonathan Atkins]

another posibility is that your driver uses hardware surface in fullscreen mode.
Alpha blits are slow on hardware surfaces without hwaccel(which practically no drivers have).
in such a case you can use a secondary sw surface and blit to that,
and then blit the changed parts or the whole thing to the real screen.
you may also consider converting the project to opengl or using glSDL.

-LIM-