using nvidia control panel software

Dell XPS, hmm? Is the bios locked out?

Didn't some of those come with unlocked bios?

You would need to up the FSB a little bit.

You would also need to watch your RAM, if you can't access it's frequency or dividers in the bios.

No voltage change would be needed. Or, shouldn't be needed.

So, open the control panel, click on devices, or device settings, then select Mobo if you can, and change the FSB there. Just drag it up a few points.

Watch the memory speed. Depending on the divider, it will go up a few points as well. Most 800 Mhz RAM should make it near 850 Mhz before needing more voltage or something else.

Guess you will have to see how much lee way Dell has given you.

--Lupi