Pentium-4 on the 478 pin boards pegged out at about 3.1-3.2 Ghz. If you dropped a 3.2 GHz cpu into your board you would see a 33% increase over your current speed. Add in Hyper-Threading found on the faster P-4's and you machine might feel significantly faster. So if you can find one of these CPU's for less than say $25, I'd go for it. But that machine, no offense intended, really is outdated; and 33% faster than slow is well, still slow. You never did say how much you have to spend, let us know and I'm certain you'll get some usfeful input.