Ok, I have the following system.

Athlon XP2000
384 megs of RAM (DDR 266)
GEForce 4 MX

I'm mostly curious what features I can dial down for the greatest effect. I
know having lots of AI traffic doesn't help, but what else really is a
system hog.

Also, what single upgrade to the above system would be most useful. I say
single, because I am a real life pilot, and thus perpetually broke