Hello All:  
 
My System:  
Q6600 @ 2.88 | MSI T2D512E 8800 GT | GA - P35 - D3SL v2.0 | Crucial Ballistix 2GB (2 x 1GB) DDR2 6400 | Thermaltake Purepower 2.0 500W PSU | Seagate Barracuda 500GB HD | XP Pro SP2
 
3dmark06 demo (stock settings): 10500
3dmark06 demo (q6600 @ 2.88): 13406
 
3DMark Score 13406  
SM 2.0 Score 5628  
SM 3.0 Score 5458    
CPU Score 4528  
 
I am having a frame rate / quality issues in games; most noteablely COD4. Lighting and shading seem to tax the system very badly and cause perforamnce drops. In game action looks very broken up, by that I mean there are horizontal lines going through the screen. I would liken it too that a CRT monitor being videotaped.  
 
If there is a bottleneck issue how can I find it? Are there any tests to see what can be causing the video card or system to not perform well? I have spent the last 24 hours trying to figure out what is wrong.  
 
I had COD4 on a Gateway FX7024 (q6600 / 3gb ram / 8800GT / 400PSU / 3dmark06 stock: 13001) playing perfectly on vista. Could it be the fact that I am running less ram? Is there anyway to check my card is performing correclty? Even in 3dmark06 the lighting effects look well below par.  
 
Any help would really be appreciated. Thanks for the help in advance!
 
David

I did some more homework and found that I have the following clock speeds in ATi Tool:  
 
For 2D: 660 / 950
For 3D Low Power  : 0/0
For 3D Performance: 660/950
 
Is that 0/0 normal?
 
Thanks  

Check if your card is running on PCIe 16x or PCIe 1x.
Check the Line Width using CPUz.
The Line Width can go down when overclocking on some boards.
You can also check speeds and get signed drivers using RivaTuner.
 
Actually your 3Dmark is not low. I don't see any performance problem from what you describe.
You may want to check your card and case cooling.

First thing is what method did you use to see if your OC on graphics card is stable? Have you checked Vsync in Nvidia control panel, if not this is called image tearing which means that you card and monitor are out of sync with oneanother. It sounds like you are describing tearing of frames in game, turn you Vsync to Force On.