Fullscreen / non-fullscreen issues

[Alkher]

OpenGL is slower than DX too

DirectX 50% faster than OpenGL ?

I cant provide a difinitive answer for you but I can say from what Ive seen from the OpenTK source not everything is done in the most optimal way (which monogame uses to handle the OpenGL stuff) and its possible that a good portion of its functionality that MonoGame uses(At the current release i believe utilizes game window?) ends up doing alot of extra unnecessary work to ensure no errors that directX may not exactly need to do.