Resource usage

Hi I wish to find out how the hardware resources (CPU, RAM) are used during a MRP run and a normal transaction. I am in a 2-tier for MRP & 3-tier for normal users environment. The AOS (MRP), TS/AOS (Normal Users), App/Web & MS SQL are all in different boxes. Thinking of adding in neccessary RAM or CPU in the correct box to enhance entire system performance. Thanks in advance for the sharing. cheers