Tested just the Vsync on and off and it didn't do anything...

Did some final testing with the latest DLLs... Bottom Line is if you run SLI will have this "HeartBeat Stutter" Problem. I've tried everything and its clearly an SLI issue.

Like it was mentioned in the Thread above about the 280 that is the right solution. Those that run the 9800X2 and any combination of SLI is going to have this problem.

I run SLI without stutter with 9800s but you need to set the SLI mode in the Nvidea control panel to "force split frame rendering".

If you are already doing that then I am clueless....

I switched from AFR to Split Frame Rendering and so far so good... It could be that I'm looking for any sort of pause but the heartbeat thing is still there. So far its much better... I only tested it a little bit. Sometimes I noticed it takes time for it to show up.

More to follow and Thank you for the Tip.

If this is the solution I will be very happy.

Glad that was some help - just another thought since you are a n Nvidea user:

Does your current stuttering increase in frequency and eventually - after an hour or so - lead to the appearance of an "OpenGL error" message? This is a known Nvidea only problem which stems from some incompatibility between IL2 code and Nvidea which was never fixed. The work around is to set up a hotkey for recording a track, then at the beginning of the mission start recording and then immediately stop recording. This somehow "resets" the memory and prevents the lock up.

If your stuttering is anything to do with memory management issues this might help even if you are never locking up - easy to try anyway as no settings need to be changed. If you use scroll lock you can tell from the light on the keyboard whether you are recording or not so you need not worry about inadvertently filling up your memory with a track.

If you get lots of flickering especially over water try putting on a little bit of light filtering in your track IR settings, i dont know how or why but this fixed it for me.

I got 2 8800GT cards running in SLI and everything runs like a dream and looks amazing now.

Make sure in the NV control panel, under 3D settings for the game you set Highest Qualety and everything else should be the NV recomended settings.

Only thing you change is you set AA to 16xQ, Override Aplication settings for AA and set Supersampling. (mines all in dutch but you figure out what i mean)

Here is my OpenGL bit of the Config.Ini file.

[Render_OpenGL]
TexQual=3
TexMipFilter=3
TexCompress=0
TexFlags.UseDither=0
TexFlags.UseAlpha=0
TexFlags.UseIndex=0
TexFlags.PolygonStipple=0
TexFlags.UseClampedSprites=0
TexFlags.DrawLandByTriangles=0
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=0

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=2
TexLarge=1
TexLandQual=3
TexLandLarge=1

VideoSetupId=17
Water=4
Effects=2
ForceShaders1x=0

PolygonOffsetFactor=-0.15
PolygonOffsetUnits=-3.0

Knocking on wood but I've never had any lock ups or errors like the one you mention.

In terms of Flickering Water I just Ctr ESC out to the desk top go back in and bingo water is fine.

So far so good.

Its really sad but I've never had this problem with ATI... Yeah my 1950 was slower but with water 2 it looked a lot better than Nvidia...

The only thing thats keeping me with Nvidia right now is every other game I run is fantastic. 2 8800gts in SLI runs just about everything maxed out at 1920X1200 with all the goodies on. This is the only game that gives me headaches and its the one I play the most.

Bang for the buck 2 GTs are very difficult to beat.

Did a lot more flying this week and the stutter problem is still very much there... It just takes a little longer for it to show up. What is odd though there are times when it stutters right out of the gate.

I hope the boyz can take a look at this for 4.090 if it ever sees the light of day. SLI is a problem with this particular game.

are there any similar problems reported with crossfire systems ?

or is this bug specific to geoforce sli systems only ?