The high density of trees (The Elder Scrolls 5: Skyrim)

In the distance the trees like twinkle, so I know when the smoothing is too high and the screen resolution is low and the texture becomes too dense. And would be okay with this flickering but when the frame too many trees, then fps sags without increasing the load on the iron. In control panel nvidia lowered the smoothing but the result is not given, except that the road became too blurred. I think some sort of item in Prefs.ini is responsible for this but not sure what. Version of the game SE