What are the purposes of your build? If you're just a gamer/casual user then the core 2 is fine, but if you plan on doing epic multitasking/video editing you might consider the quad. Personally I'd suggest that you wait until you have more money (and your computer is no longer doing what you want it to) and upgrade to an i5/i7 build. The 775 platform is basically dead now and I would advise you not to get another one of those chips.