As far as I understand, dual core means two more or less complete processors (perhaps sharing some levels of cache) on the same piece of silicon. Each of them can possibly have multiple hardare threads ('hyperthreading') capability, that is, capability to simultaneously process more than one independent instruction stream.

So, your machine will benefit from a dual-core processor the same way it would from two single-core ones (except that cache-coherency processing might be a tad faster when the procesors share the die). A particular CPU-intensive single-threaded task will not run any faster, but anything more parallel than that (e.g. the whole managerie of 'system' tasks) will.

Now perhaps someone actually having a clue about this could take over