Voltage droop reduction using throttling controlled by timing margin feedback

An active processor throttling control loop using critical path timing measurements is enabled in the shipping POWER7™ based P775 supercomputer to prevent voltage droop induced failures. As a result, worst-case workload-induced voltage droop events are reduced by more than 50% compared to the system operating without the control loop. The reduction in operating voltage afforded by this technique translates to significant yield improvement, reduced failure rates, and improved power efficiency.