Method of exploiting spare processors to reduce energy consumption

A method, system, and computer program product for reducing power and energy consumption in a server system with multiple processor cores is disclosed. The system may include an operating system for scheduling user workloads among a processor pool. The processor pool may include active licensed processor cores and inactive unlicensed processor cores. The method and computer program product may reduce power and energy consumption by including steps and sets of instructions activating spare cores and adjusting the operating frequency of processor cores, including the newly activated spare cores to provide equivalent computing resources as the original licensed cores operating at a specified clock frequency.