It's not AA, Dynamic Lighting and Dynamic shadows are the 2 biggest performance hitters.
If you want best visibility for enemies, turn everything on low except put Geomitry on high (so you can see things farther in distance) and Effects on High (so you can see jet trails better and bullets hitting walls etc) and draw distance on high (for obvious reason).
Terrain set to low is a good one, say an enemy is hiding on a hill in front of a "weak" texture, you'll be able to see him if terrain is set to low, even though you won't be able to hit him, it's useful
As you seem new to this game, test it out, go to the Warehouse on Karkand with lighting set to "high" it's almost pitch black.
Try it with lighting set to "low" and you can see everything, you'd get owned in those situations if you had lighting set to high.
Not to mention you'll have a consistent high framerate and it will look cleaner and smoother, so you'll have the chance to be a better player from that as well
Last edited by H3RB4L ABU53 (2010-03-10 10:36:22)