I was wonder what some of your guys take on this was. I've looked up some info on both and I can't really decide which is best for me. Feel free to give you input or let me know if I got any of this wrong. I use my computer for mostly games (about 70-80% of the time). Last game I beat was FEAR and Quake4 before that and I play Battlefield2 on and off for weeks at a time, oh and I play this little game that probably none of you have heard of. . . .World of Warcraft hehe. Other things I do regularly are music, various web applications/downloads (IE large demo files), CD-Burning (though not that often), have a DVD burner but only burned one DVD, and making ISO files off of, well never you mind of what hehe I'm looking at either a 3800+ dual core or a 4000+ san diego core single, I know these are equivalent but you know what I mean and the single is only bout $12 more than the dual) The following is some of the stuff I've gathered. I've heard dual-cores are slower in single applications than there single core brothers. So running one just to do games it would get slightly lower frame rates and performance. But I've also read that they are great at running more than application, currently I'm running as I type this, Norton 06 (I know it's a system hog but I had a virus rape my computer hardcore before), AIM, 3 IE windows, MSWord2003, Windowblinds, wireless network software, and I know there is a bunch of X-Fi software running in the background too. So I would think that using a dual core for that and running a game I would get much better performance than a single. Last I've heard the Manchester core overclocks like crazy and that I could easily get 4400+ speeds out of it which i like to overclock, I do plan on getting a Zalman CNPS9500 for either that I get, so getting the most I can on reasonable temps is good. On the single core side I've read that the San Diego cores are the best. I forget exactly/completely why (feel free to help me out), but I think had to do with the bigger cache and clock speeds? And as I said before I've heard they are better for single applications like running games or benchmarking with 3DMark (I love that program! though I never get any outstanding scores). I saw on tomshardware.com where they compared many different processors against each other and the san diegos were always towards the top (granted the FX ones were at the very top) and the duals were usually in the middle/lower portion and that the dual cores were always much much lower than the same speed rated single cores (like X2 3800+ VS normal 64 3800+). In that regards it makes me think a 4000+ san diego might be good for me? what are your thoughts on this? Any people that had dual cores what do you think compare to singles you use to have or use?