There really isn't any need at all to overclock your 6800, if you've got a new system i would just use it as it is, the 6800 will run new games such as HL2 / Doom3 on full graphics at a very nice frame rate, even at multiplayer level.
There really won't be that much performance gain for you, and you risk the fact that you might damage the card..
and i wouldn't use Riva Tuner i would use the inbuilt overclocking utility called "Coolbits 2.0"
goto your desktop: right click, goto properties, goto "Settings", at the bottom of the box, click "advanced" - in the new box thats opened select the tab that says: "GeForce 6800" now you'll get a small menu appear as an addon on your left of the new box, select "Clock Frequency Settings", then you select: "Manual Overclock".
Make sure you have selected "Performance 3D" under the drop down menu called "settings" (by default it says "Performance 2D")
Now don't do anything yourself.. here click the: "Detect Optimal Frequencies"
This will safely find your cards maximum overclock - and it doesn't take long :)
If you don't have this option available it's because its hidden, Nvidia disabled it automatically via a registry string, so download and run this:
Enjoy :good:
