X2 6000+, only 2GB RAM, and an older 3850 with only 256MB...
1280X1024, 2XAA, 512 for ABRIS, Skhival, etc, civ traffic, scenes high, beautifull watter, and the only setting with real impact: textures medium, caused by my 256MB video card (otherwise I have a little shuttering). And a medium visible range.
I have in "Battle" a maximum drop of 18-20 FPS. The average is 40. I set the maximum of 50. I reduce "effects" (put in 2), because the "fog/dust" needs some optimization. The simmulation runs well in my 6000+ system.
Something strange in hyperfighter system. Mine is worse and runs better.