Verified answer

the advantage of a dual core, quad core...processor is it ability and the way it deals with data transfer to and from. Single core is fine pending on what your doing but it has got nothing close to the ability to multi task as the newer hardware. Just don't be fooled by ones experience. A single core of 3gig speed does not even compare to the dual core at 1.5 per. The way it transfers data is totally different.

Processor speed is important for overall computer speed but there is more to it than just processor speed. Ram size and speed is important, so is processor cache, and front side bus speed. A fast processor is useless unless the rest of the computer is able to keep up. Even hard drives had different speeds of both rotation and data transfer. Of course dual core has the advantage of being able to process two things at once where as a single core does one thing while the second task takes a short backseat. But like I wrote, it's not the only thing to consider. Hope it helps.

I would say 3gig is better for now. Most 64 bit are running 32 bit programs. 3GHz is actually faster until the programs catch up with the processors.

The 1.5GHz, because its a dual core which means it is doubled and can put out more.