With myself and Painless recently getting nVidia 8800 GT cards, we found that although we got lovely perfect settings, we also experienced Vertical Shearing of the cockpit when using head tracking software. It took us a day or two to find the solution, so here it is for those who go down the same route as ourselves.
You can alter some of these settings of your own conf.iie in order to get the right FPS for your PC. But to get PERFECT settings, like the lovely water, you need HardwareShaders=1 set.
conf.ini
[Render_OpenGL]
TexQual=3
TexMipFilter=3
TexCompress=0
TexFlags.UseDither=1
TexFlags.UseAlpha=0
TexFlags.UseIndex=0
TexFlags.PolygonStipple=1
TexFlags.UseClampedSprites=0
TexFlags.DrawLandByTriangles=1
TexFlags.UseVertexArrays=1
TexFlags.DisableAPIExtensions=0
TexFlags.ARBMultitextureExt=1
TexFlags.TexEnvCombineExt=1
TexFlags.SecondaryColorExt=1
TexFlags.VertexArrayExt=1
TexFlags.ClipHintExt=0
TexFlags.UsePaletteExt=0
TexFlags.TexAnisotropicExt=1
TexFlags.TexCompressARBExt=1
TexFlags.TexEnvCombine4NV=1
TexFlags.TexEnvCombineDot3=1
TexFlags.DepthClampNV=1
TexFlags.SeparateSpecular=1
TexFlags.TextureShaderNV=1
HardwareShaders=1
Shadows=2
Specular=2
SpecularLight=2
DiffuseLight=2
DynamicalLights=1
MeshDetail=2
VisibilityDistance=3
Sky=2
Forest=3
LandShading=3
LandDetails=2
LandGeom=3
TexLarge=1
TexLandQual=3
TexLandLarge=1
VideoSetupId=17
Water=4
Effects=2
ForceShaders1x=0
TypeClouds=1
PolygonOffsetFactor=-0.15
PolygonOffsetUnits=-3.0
NVIDIA Control Panel - Manage 3D settings
IL-2 Sturmovik: Forgotten Battles + Ace Expansion Pack
You can set your AA, AF and all settings as you see fit for your PC spec, but to prevent Vertical Shearing, we found this solution -
MULTI-DISPLAY/MIXED-GPU ACCELERATION = MULTIPLE DISPLAY PERFORMANCE
TRIPLE BUFFERING = OFF
VERTICAL SYNCH = FORCE ON