here ya go ... this was sorta my base for setting up w/ 512 ram and a 128 video card (nothing preloaded , skins enabled)

distance is maxed ... and performance slider was at about 3/4's to 1 inch from left (full tilt) move it to the right a touch if your getting stutters in the game
notice the ram over head amount .. thats the secret ... if your getting up near 90-95 % of your total ram used in normal flight your game should be stuttering in dogfights and even worse in high traffic (graphics) area's ...
You want to keep a 10-20% overhead of ram in the worst conditions . dont try to use all avail ram as it wont work .
----- now for 1024 up and hires pack running ---
ram ussuage on some pc's run in the 380-400 area , or runs at 700 area used
depends on preload and skins I think .. and if your set at 2x 4x ect AA .
also when comparing frame rates the Clipboard snags 10-15 fps when its up .
hopefully this give you an idea of how to tune the game ... this really helps on the slower pc's and can cure stutters/lag on the faster ones.
note some of the SEA terrains take a big bite outta your ram and the slider may need moved down alittle more to gain fps .
final note on stutters is sometimes the sound files when played will cause a freeze/stutter to ... to fix this turn off that sound in AH and it should go away .