Got an Opteron 146 OC'ed to 2,8 GHZ and a OC'ed Nvidia 7900gt 1280 x 1024 running with mirrors, heat blur, civ traffic everything
else on max exept water on mediun ( cause i think it looks best that way, higher settings look way to glossy to me )
and Vis-range,the worst of all FPS killers, on low.
I have compensated the low Vis-range by tinkering with the " optimizations" options in the LOCFG tool.
I get 30 - 60 everage FPS depending on if im flying offline for myself, or more complex online missions with loads of Air and ground targets.