Forgive me for "butting in" seeing as that I havent read the 8 or so pages after the first comment....but.....
If you want you computer to go any faster I'll suggest getting some more ram... getting a bigger processor probably won't give you any visiable difference.
You might even want to just get some different ram, seeing that you own a dell, and they use the cheapest everything on the planet, the ram sucks.
If you still all pissy about getting a better processor you should attempt at overclocking it. Because its a dell and they don't want you overclocking it because its parts probably can't handel it, there is no overclocking anything in the bios. You'll have to use a program to do it for you, i recommend useing Clockgen which lets you adjust the FSB. You will also probably have to get a new psu (power supply) for the dell If you havent already. The dell one just can't handel the load. You might also want to get a new fan, because the dell's ones aren't very good (some over heat just on stock.)
Don't think Im downing on dell, I have one of their laptops. Plus you should try building a computer with the same spec.s and see how much it costs.