I uninstalled the old 8.1 cat drivers using the ATI Uninstall Utility, then installed the latest drivers. I may give it a try with 8.7 beta, thanks a lot for the link.
I will also post some of my conf.ini settings.

Just learnt a tweak to control the idle temps, heard it's toasty on the stock units.

If you make a profile in catalyst after turning on Overdrive( make sure clock and memory settings are correct). You can then go to the file "C:\Users\your computer name\AppData\Local\ATI\ACE\your computer name. XML. the xml file will have the same name as the catalyst profile you saved. right click and hit edit.

<Feature name="FanSpeedAlgorithm_0">
<Property name="FanSpeedAlgorithm" value="Manual" />
</Feature>
<Feature name="FanSpeedRPMTarget_0">
<Property name="Want" value="0" />
</Feature>
<Feature name="FanSpeedPercentTarget_0">
<Property name="Want" value="65" />

Change the value to "manual" and Want value to "65" (% of fan speed)

Save the file then reload your profile in catalyst.

For fellow XP'ers it's under C:\Documents and Settings\"your computer name"\Local Settings\Application Data\ATI\ACE\Profiles.xml

Knocked 10 degrees off idle and 5 off load on here.

Wow did not realized that this would start a NVIDIA vs ATI debate but well...

I used to have an ATI850XT prior to buying a pair of BGF 7900GTX OC cards (on sale BTW). Like most I saw a reduction in picture quality when going to NVIDIA. I now have flicquering that I did not have before. Could be an SLI thing, I'm just not that familiar with NVIDIA's cards. My previous ATI card had no problem running iL2 under open GL and gave a great image (no flickering costline/runways/invisable roads)... Also spotting planes was a lot easier... we all know how this is important LOL

I was thinking of going back to a single 4870 for now and buying a second in the future. So going with a single card could eliminate a lot of the SLI (or Crossfire) related stuff...

I know that this sim is VERY CPU intensive. Hell an OC of 0.2 will give you about 10% more FPS... So to all of you out there overclock those #$%?&*. Mine is overclock up to wasooo as it only have to live for about 6-8 months (new Intel chips are coming with the X58 platform).

So what is it GOOD with iL2 or NOT... its the ONLY game that I play.

As said before - my settings, probably wrong for HD4850

[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=0
TexFlags.TexEnvCombineDot3=1
TexFlags.DepthClampNV=0
TexFlags.SeparateSpecular=1
TexFlags.TextureShaderNV=0

HardwareShaders=1

Shadows=2
Specular=2
SpecularLight=2
DiffuseLight=2
DynamicalLights=1
MeshDetail=2
VisibilityDistance=3

Sky=2
Forest=2
LandShading=3
LandDetails=2

LandGeom=2
TexLarge=1
TexLandQual=3
TexLandLarge=1

VideoSetupId=8
Water=2
Effects=2
ForceShaders1x=0

PolygonOffsetFactor=-0.0625
PolygonOffsetUnits=-1.0

Very similar config to mine dflc03, not sure if this might help but try changing all the entries with "NV" to a value of 1 eg:

TexFlags.TextureShaderNV=0

TexFlags.TextureShaderNV=1

Think the zero value is specific to nvidea cards.

@smartDalek

"Think the zero value is specific to nvidea cards."

there you got it wrong, matey.

You set 1 if there IS a nvidia-card installed.

My mistake robtek, thx for the correction.

Have it at 1 on this rig, thought I'd reset it, apparantly not.

Knew I changed values on the old rig but so long ago I forgot which value.

So, basically the settings are right and the overall result is wrong :confused:

dflc03 have you tried going into il2 setup and resetting the the vid cards preferences?, maybe it might cure the problem by choosing a more appropriate setting, fwiw I chose max settings and no probs here.

I am on max settings...and a world of trouble. Tried also the 3XXX settings, nothing better