well i try both,,, but it happen that dual core had only small different from the single core...from multitasking etc....sometimes from the dual core it make me stop when you are in instant messaging,,,not like the single core it is good also from other application, but its true dual core had a good speed but sometimes it stop....and also it is expensive coz your using two brain...and it make me crazy with the price the performance of dual core are in great speed but single core with Hyper-Threading makes a single processor appear as two logical processors by having two separate architectural states,

In my experience, if you don't do LOTS of multi-tasking, the Pentium D processors are the fastest so far. That was the first processor type that Intel called "dual core" ...... but it wasn't really "dual core" as we know it now - it just had two lots of Level 2 cache memory.

We supply lots of new Dell laptops and desktops to home users and small business customers and we still recommend single core processors more than dual core processors.