On the Interplay of Parallelization, Program Performance, and Energy Consumption

• Published in: IEEE transactions on parallel and distributed systems Vol. 21; no. 3; pp. 342 - 353
• Main Authors: Sangyeun Cho, Melhem, R.G.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amdahl's law; Architecture; Concurrent computing; dynamic voltage and frequency scaling (DVFS); Dynamic voltage scaling; Dynamics; Energy conservation; Energy consumption; energy-delay product (EDP); Frequency; Microprocessors; Multicore processing; Multicore processor; Optimization; Parallel processing; Processors; Radio spectrum management; Resource management; Resources management; Serials; Studies; Surges
• ISSN: 1045-9219; 1558-2183
• DOI: 10.1109/TPDS.2009.41

This paper derives simple, yet fundamental formulas to describe the interplay between parallelism of an application, program performance, and energy consumption. Given the ratio of serial and parallel portions in an application and the number of processors, we derive optimal frequencies allocated to the serial and parallel regions in an application to either minimize the total energy consumption or minimize the energy-delay product. The impact of static power is revealed by considering the ratio between static and dynamic power and quantifying the advantages of adding to the architecture capability to turn off individual processors and save static energy. We further determine the conditions under which one can obtain both energy and speed improvement, as well as the amount of improvement. While the formulas we obtain use simplifying assumptions, they provide valuable theoretical insights into energy-aware processor resource management. Our results form a basis for several interesting research directions in the area of energy-aware multicore processor architectures.