Yesterday, I installed the latest Nvidia Driver (91.47) to my
GeForce 7800GTX Video Card.

I used Noell's absolutly outstanding guide to replacing drivers.
(We are lucky to have guys like him. Thank You Noell)
It's a sticky at the top of the Hardware Forum.

I have noticed a definite FPS boost. About 5-8 FPS.

I just flew the Maule Orion all around the Dallas/Ft Worth, Tx area.
1. Below 1000ft I get 13-15FPS. Smooth with just a small touch
of jerk.
2. Above 1000ft I get 20FPS all the time. (locked at 20FPS)
Just as smooth as a new born babies-you know what.
3. Crystal clear scenery in all views at all altitudes.

Update your drivers, follow the instructions, can't go wrong.