What about framerate (from 10 to 20) What does it do? It definitely is not a refresh rate, because there is a different option for this.
Also noticed that on draw distance more than 900-1000 the game starts to lag.
even at 1500 draw distance.
Just really nor smooth enough, especially visible if you just played with draw distance at 900.
Don't know about fog, but the terrain and buildings could been seen much farther away than 500m.