This thread is probably most useful to you: http://www.tomshardware.co.uk/forum/320983-10-dual-core-core
Quote from thread:
"you cant compare a "dual core" cpu to a core 2 duo, simply because the core 2 duo IS a type of dual core CPU. A "Dual Core" CPU is NOT a type of CPU, it is a term used to describe ANY CPU with 2 cores. A core 2 duo can't be faster than a dual core because it IS a dual core, as are many other types of DUAL CORE CPU's!!!!!!!"
In short, basically it comes down to whichever CPU's your comparing as to which is better