[Boost-users] boost::thread and dual (quad) core CPU(s)

Hello, I've developed small application which has a few threads. So far I'm using only single CPU (one core) and my question is: what will happen if I'm using more CPUs (or cores)? Whether threads will be automatically executed on different CPUs in parallel or not? If not what is a solution to run them in parallel? Unfortunately currently I have no access to multi-processor machine to check it myself. Regards, Bartek