about NIOSii 12.1 vs multi-core

Hi, I run the NIOSii 12.1 appear with one question,I have two cpu,then I wish my SOPC can do multi-core. I use Launch Group(Run-configuration-Launch Group).I already add two cpu to Launch Group,but two CPU can't execution at the same time.It can that one by one run cpu. So, How can I do that can execution at the same time.