I use a Ge-force4mx 440 Agp8x with 128 MB vram. My Pc is 1.51 Ghz, running xp pro with 768 MB RAM. I usually get about 12-20 fps which, as you probably know is not very smooth. I was just messing about with FS the other night and, without changing any settings (I keep all my sliders very close to or at full) I was able to get up to 38 fps.

(note of caution: If you try out what I describe below, I cannot be held responsible for any damage made to your computer, however, the changes are all simple and shouldn't do any harm. If you are unsure, I would check with others first)
Ge-force 4 users, this could be your answer.
All you need to do is go to your settings/display tab by pressing alt in flight or using the main menu. Then go to your video card page and change your fs9 resolution (I changed mine to 1280 x 1024 x 32, but you need to set it to something high, more than 1152x864 I think). Then exit your sim, on your desktop, right click with the mouse and go to properties (or go to start, settings, control panel and open 'display'). Go to the settings tab and click on advanced, go to your video card tab and open additional properties. Then all you have to do is manually set your anti-aliasing settings to 2x or quincunx. When I tried the sim, the graphics were still great because it was at a high resolution and the anti-aliasing smoothed off the edges. I'll be posting screenshots later in the freeware screenshot forum. Hope this works,

Good luck,
Adam.