thanks for all advices and recommendations, so now i have ssao&vsync OFF, AA 2x, fullscreen ON, building textures: medium, all the rest is set to high
im having now a very good fps (average 30-35fps) in missions with lots of different ai hardware here and there etc
i tried the quickmission flying over London with the previous settings set to full: i got 11fps (instead of 4-6fps before)
)
but there is still something weird: despite that im having GRASS set to ON, i have never seen it! everything is dead flat