An optimal analytical solution for processor speed control with thermal constraints

As semiconductor manufacturing technology scales to smaller device sizes, the power consumption of clocked digital ICs begins to increase. Dynamic voltage and frequency scaling (DVFS) is a wellknown technique for conserving energy. Recently, it has also been used to control the CPU temperature as part of Dynamic Thermal Management (DTM) techniques. Most works in these areas assume that the optimum speed profile (for either minimizing energy or maximizing performance) is a constant profile. However, in the presence of thermal constraints, we show that the optimal profile is in general, a time-varying function. We formulate the problem of maximizing the average throughput of a processor over a given time period, subject to thermal and speed constraints, as a problem in the calculus of variations. The variational approach provides a powerful framework for precisely specifying and solving the speed control problem, and allows us to obtain an exact analytical solution. The solution meth...

• Type: Conference
• Year: 2006
• Where: ISLPED
• Authors: Ravishankar Rao, Sarma B. K. Vrudhula, Chaitali Chakrabarti, Naehyuck Chang
• Keywords: ISLPED 2006, Optimum Speed Profile, Speed Profiles, Thermal