I want to run simultaneously several instances of computation-heavy program on quad core system with RedHat. How do I specify the core to be used by each of the processes? How do I check the core used by already running processes?

And more: /proc/cpuinfo says it is Quad Core Xeon, but system monitor shows only one indicator ~25% loaded for each heavy process. What's wrong? Can I see the process-core distribution? Using smp kernel 2.4