Dual core won't do anything for POSER... but... having 2 cores means the OS can do hard stuff on one processor, while Poser works full speed on the other. So you will probably see a small improvment over a single core at the same speed.

mo·nop·o·ly  [muh-nop-uh-lee]
noun, plural mo·nop·o·lies.
1. exclusive control of a commodity or service in a particular market,
or a control that makes possible the manipulation of prices