User-And Process-Driven Dynamic Voltage and Frequency Scaling

The authors describe and evaluate two new, independently-applicable power reduction techniques for power management on processors that support Dynamic Voltage and Frequency Scaling (DVFS): User-Driven Frequency Scaling (UDFS) and Process-Driven Voltage Scaling (PDVS). In PDVS, a CPU-customized profile is derived offline that encodes the minimum voltage needed to achieve stability at each combination of CPU frequency and temperature. On a typical processor, PDVS reduces the voltage below the worst-case minimum operating voltages given in datasheets. UDFS, on the other hand, dynamically adapts CPU frequency to the individual user and the workload through direct user feedback.