...grab an axe
sorry, couldn't resist after I read it in somebody's signature...
sorry, no solution but if you upload a track, I can run it on my SLI setup and tell you whether there is difference...
I have set the trees to "very low", land details=high and grass=on and like it, I think the game has too many trees, probably they were thinking about the CO2 offset to the electricity our new GPUs will consume running the game...
~S~