Processor Energy and Temperature in Computer Architecture Courses: a hands-on approach

Performance has driven the microprocessor industry for more than thirty years. Its effort has enabled to multiply by several orders of magnitude the computational power; e.g., the Intel 8080 was able to execute 0.64 MIPS and the newest Core i7 can execute 6400 MIPS. The cost of this fabulous improvement has been a large rise in energy consumption. Nowadays, we have reached a point where one of the most limiting factor for improving performance is energy dissi-pation. In order to keep the performance improvement during the next years, it is necessary to study energy and tempera-ture in deep. Nevertheless, most current computer architec-ture curricula include neither energy nor temperature. The lack of adequate experimental platforms contributes to the difficulty in teaching these topics. In this paper we propose a possible solution: to instrument a commodity PC for measuring the processor power and temperature during the execution of real programs. The platform is devised for teaching, but it can be used to support research experiments as well. For example, we describe an interesting under-graduate laboratory that analyzes the interaction between compiler optimizations and energy. With this laboratory, students can learn that performance optimizations usually reduce energy but may increase power.