Quote from rmorse:
For most traders, unless your using VERY large spread sheets or programs that use a lot of audio or video resources, high clock speeds and very large blocks of ram make very little difference. Even a quad core running WIN XP with 4GB of ram with a clean hard drive will run very well. I was an options market maker with this set up making markets in 15 options this way. Every strike, every month very math intensive and never used more than my ram or 60% of my CPU. With that said, with a WIN 7 machine I would get at least 8GB of ram. High clock speeds as long as you stay in the I7 family will not be noticeable.
Your trading machine will be slowed down by a 7500 RPM drive. The hard drive is in constant use. It's used for virtual ram, reading and writing data. A 10K RPM drive with the new sata connection will do more to speed up you machine's performance than over clocking. Unfortunately, Dell charges a large premium when you add products like this.
I've been building my own computers for years by buying my parts from Newegg.com. Do you have any friends to help you try that? The machine will be less expensive, have only the parts you pay for and more importantly, have a clean install of win 7 with no other crap added.