Analysis of Energy Reduction on Dynamic Scaling-Enabled Systems

Abstract

Dynamic voltage scaling (DVS) is a technique that varies the supply voltage and clock frequency, based on the computation load, to provide desired performance with the minimal amount of energy consumption. It has been demonstrated as one of the most effective low power system design techniques, particularly for real time embedded systems. Most existing work are on two different system models that enable DVS: the ideal DVS system that can change its operating voltage with no physical constraints, and the multiple DVS system that has only a number of discrete voltages available. Although the ideal DVS system provides the theoretical lower bound on system’s energy consumption, it is the practicability of multiple DVS systems and the emergence of other DVS-enabled systems, which do not fit either model, that challenges system designers the following questions: should DVS be implemented in the design or not? if so, how should DVS be implemented? In this paper, we answer these questions by studying the DVS-enabled systems that can vary the operating voltage dynamically under various real-life physical constraints. Based on system’s different behavior during voltage transition, we define the optimistic feasible DVS system and the pessimistic feasible DVS system. We buildmathematical model for each DVSenabled system and analyze their potential in energy reduction. Finally, we simulate a secure wireless communication network with different DVS-enabled systems. The results show that DVS gives significant energy saving over system with fixed voltage. Interestingly, we also observe that although multiple DVS system may consume more energy than the theoretical lower bound, the optimistic and pessimistic feasible DVS systems can achieve energy savings very close to the theoretical bound provided by the ideal DVS system.