i think it was setting the ugrid to 9, dropped it to 7 and it seems to work. But now I have the problem where the game will suddenly crash (no error message) within a few minutes of starting (again doesn't happen with standard settings). I think that's also cause by the grid loading option. I don't why, my computer should be able to handle at least 7. I mostly changed the draw distances, number of decals, water quality, cheked the 'threaded' boxes etc.