I have been having texture problems with FSX. The textures would be clear and sharp at load up and in matter of a few seconds or minutes the textures would go completely blurry. Other than that the game ran ok.....with no autogen or complexity. So I upgraded from a XFX Geforce 6800 to a eVGA 7800gs. Helped some but if I put autogen or more complexity to the scenery it would eventually go blurry and the framerates werent "awesome". I had been wondering if I was getting all I could out of a 64 bit processer with out the 64 bit OS. So I downloaded the Windows Vista Beta RC1 x64. Once I got it all loaded and installed the x64 nVidia drivers for Vista I loaded FSX. Big difference. I didnt get to play long but the frame rates were better, I didnt lose textures, and I could set the autogen and complexity to very dense. Slight chopiness in the frame rates but nothing compared to XP Pro. I would say 10x improvement. These are just prelim results and I will hopfully get to tweak more tonight and see if is a stable fix.
Athlon FX 64 3200+ 2.0Ghz
1Gb DDR 400 RAM
eVGA Geforce 7800 GS AGP
Windows Vista BETA RC1