I'm testing some software on a particular four core machine. Is there an option for
top or a similar utility that can tell how much each core is being used for a particular job?
mpstat is part of the the sysstat package.
Output look like this -
This page will be helpful for you - http://www.cyberciti.biz/tips/how-do-i-find-out-linux-cpu-utilization.html
htop. Configurable, detailed, and a little more user friendly than standard