Hello;I have a San Diego Athlon64 4000+ Socket 939 1meg L2 Cash,Running Stable at 2.8Ghz's Single core cpu..I'd like to know what Dual Core Athlon 64 Socket 939,will really make a difference without spending a lot of money?? Or should I just stay with this single core 4000+.??? Any Idea's?? I want to update this 939 1 more time maybe.?