The Prescott will be faster, especially since it has a faster FSB. You're talking about a 20% increase in clock speed as well plush the addition of hyper threading. It would be a noticeable upgrade, but keep in mind that it's still rather meager compared to todays entry level CPUs. You're looking at performance around, or even a bit less than, a $33 AMD Sempron 140. In light of that $95 hardly seems worth it. If you can overclock the CPU, which I doubt since you have a Dell, and have a decent cooler for it then the proposition looks a little bit better. Even so I would suggest buying the chip on eBay or something from a power seller.