cpu question

[OS-Wiz]

In what situations do you take advantage of multiple cores? Will a CPU with 4 cores be twice as fast as a dual core CPU when 4 or more programs are running?

You'd have to frame that question a little tighter to answer it. If you had 4 apps, each loading the CPU cores (e.g not off doing an I/O fetch which puts very little load on the CPU) and the core speeds of both CPUs were the same, then yes, you'd see nearly a doubling of performance. However, if the two core CPU was twice as fast as the four core CPU, then you'd see very similar performance for both.