My framerate jumped from 15FPS to 30FPS on taxiways in multiplayer DCS World 1.2.0.
I have i5 2500K@4.5Ghz, 16GB DD3, 60GB SSD and AMD HD6770 1GB graphics card...
HDR Cold, 4x MSAA, all High except Water on Medium and Civ traffic Off, Fulscreen, Vsync on, TSAA off, Disable aero On, Cockipt shadows off (due to bug), Clutter 250m, Trees 6000m, Preeload maxed out, Tree shadows off.
I use SoftH as an inbetween layer... no extra monitors... and MAXFPS=35 in graphics.cfg