Power management in the Intel Xeon E5 v3

The Intel Xeon E5 v3 family is the latest generation of enterprise-grade, high-performance, Xeon microprocessors. It implements several new power-management technologies and features aimed at improving power/performance efficiency, increasing performance, and improving power delivery. It is the first commercial x86 processor to manage voltage/frequency optimizations on a per-core granularity. This is done by combining a) fine-grained on-die per-core voltage regulators, enabling every core on the processor to run at a different voltage, b) per-core clock management, enabling each core to run at a different frequency, and c) advanced power management algorithms for optimizing the frequency and voltage of each core based on OS requests, system utilization, on-die sensors, and silicon characteristics. The Xeon E5 v3 family also introduces a new maximum-power-draw (Pmax) management approach. This paper describes some of the technical challenges, solutions, and lessons learned during the architecture, design, and productization of this new generation of microprocessor architecture, as well as the power/performance improvements measured for server workloads.