Servers--high-end, multiprocessor systems running commercial workloads--have typically included extensive cooling systems and resided in custom-built rooms for high-powerdelivery. Recently, as transistor density and demand for computing resources have rapidly increased, even these highend systems face energy-use constraints.

Commercial-server energy management now focuses on conserving power in the memory and microprocessor subsystems. Because their workloads are typically structured as multiple application programs, system-wide approaches are more applicable to multiprocessor environments in commercial servers than techniques that primarily apply to single-application environments, such as those based on compiler optimizations.