If you're a gamer, you might want the 3.2 GHz for more processing power. If you want a more well-rounded system, go for dual core. Several applications are multithreaded and will take advantage of the dual core. This means running more applications at once (and more smoothly), and some software could even run faster. The current Maximum PC magazine states a DVD backup program will run much faster with dual cores.
I recently had the same dilema. After some research, I chose the dual core 2.8 GHz, to be more "future-ready". My new Dell will get here next week, and I can't wait. Hope this helps.
I recently assembled a computer on the Dell website. I'm not a computer guy by any means, I just want something I can check email with and download movies and music, maybe games. Right now I'm torn between an Intel Pentium D Dual Core Processor (2.8GHz, 800FSB) or an Intel Pentium 4 HT Processor (3.2GHz, 800FSB) Everyone says that Dual Core is the way to go, but why is the other one $50 more? I obviously want to have the better of the two. Can anyone help me out?