overclocked video cards question.

No.

Performance depends on more than one component/factor. If your CPU is slow and/or you have insufficient system RAM and/or you have slow hard drives and/or your PC heats up due to bad ventilation and/or 'and so forth', no amount of overclocking of your video card will give you any increase in frame rates whatsoever. If your temps are high, your performance may actually drop if you OC the card further increasing the temps.

On the other hand, if your video card is slow while the rest of your PC is straight out of the 24th century you may get an insane performance boost by overclocking your video card by 15%.

Now, the above was some general stuff to show you how things work.

To answer your question about about the 8800 GTS specifically.. WHY in the world would you need to OC that? Games running too slowly? *ugh...*

No.

Slava's explination is pretty good.
When you overclock a powerhouse like the GTS it may become limited by other componet's like your cpu and ram.

Not compleatly correct, though.
As far as I know, untill the cpu or gpu hit their Tjunctions, the temp where it is throttled back, you should still get gains from the overclock.

Not shure what the Tjunction on the 8800GTS is, but would be intrested if anyone knows what it is?

I have this card with a good overclock on it now.
At ~20% OC core and mem (620/950) I get ~14% increases.
This is based on my final 3D Mark '06 stability runs.
With stock settings I was getting ~9000, with 20% OC, ~10500.

You may have to overclock your cpu to get the true potential from this card.
What is it in BTW?