1. A method for measuring use of a plurality of physical processors in a multithreaded system, comprising: measuring a logical usage percentage of each of a plurality of threads available in a computer system comprising a plurality of physical processors running said plurality of threads; measuring a physical usage percentage of said plurality of physical processors by each of said plurality of threads by retrieving, from each of said plurality of physical processors, a register value holding a number of instruction dispatching cycles received at each processor for each of a selection from among said plurality of threads executing on each processor and calculating said physical usage percentage of said plurality of physical processors by each of said plurality of threads based on the percentage of said number of instruction dispatching cycles received for each of said plurality of threads; calculating a percentage usage of a total capacity of said plurality of physical processors from said logical usage percentages and said physical usage percentages by calculating a plurality of usage factors by multiplying said logical usage of each of said plurality of threads with said physical usage percentage corresponding to each of said plurality of threads, calculating a usage sum by summing said plurality of usage factors, and calculating said percentage usage of said total capacity of said plurality of physical processors by dividing said usage sum by the number of said plurality of physical processors.