Version 1.0 Technical Report No. VT/CS-09-19 August 31, 2009 Report of the Science of Power Management Workshop April 9-10, 2009 Arlington, VA Kirk W. Cameron, Virginia Tech Kirk Pruhs, University of Pittsburgh Sandy Irani, University of California, Irvine Partha Ranganathan, Hewlett-Packard David Brooks, Harvard University This workshop was sponsored by the National Science Foundation (www.nsf.gov). The views expressed in this report are those of the individual participants and are not necessarily those of their respective organizations or the workshop sponsor.Version 1.0 Technical Report No. VT/CS-09-19 August 31, 2009 2 Table of Contents Preface 3 Executive Summary 4 Background 4 Key Findings & Recommendations to NSF 6 Conclusions 9 Appendix A: Organizing and Steering Committee 10 Appendix B: List of Attendees 10 Appendix C: Detailed Reports by Break-Out Group 12 Software 12 Data Centers 16 Hardware 22 Networks 26 Storage 30 Physicals 35Version 1.0 Technical Report No. VT/CS-09-19 August 31, 2009 3 “The energy used by the nation’s servers and data centers is significant...more than the electricity consumed by the nation’s color televisions and similar to the amount of electricity consumed by approximately 5.8 million average U.S. households.” EPA Report to Congress on Server and Data Center Energy Efficiency. In response to Public Law 109-431, August 2, 2007. Preface A number of reports in the past several years have questioned the sustainability of the computing infrastructure of the United States. Reports by the U.S. EPA and others have concluded that in order for the U.S. to maintain its competitiveness the power and energy consumption challenges facing our IT infrastructure must be addressed. Power consumption of IT equipment begins with the design of a microchip and continues across the traditional technological boundaries of system design integration and design of the facilities that house them. Since most techniques have been developed in isolation, there are serious gaps in our understanding of the “science” behind these complex systems across and within these boundaries. In recognition of recent developments, NSF sponsored a Workshop on the Science of Power Management on April 9-10 in Arlington, Virginia. The intent of the workshop was to bring together leading thinkers in the area of power and thermal management from chips to systems to facilities and integrate them with algorithm and theory experts to identify, prioritize and recommend promising research directions in the hope of incubating development of a science of power management. The format of the workshop was a series of keynote talks from industrial experts and academic leaders followed by breakout sessions focusing on software, hardware, networks, storage, and physicals. Break out groups met twice and group leaders presented their findings to the committee and attendees to close the workshop. The steering committee was tasked with authoring this report and releasing it to the public upon delivery to NSF. This document contains an executive summary of the key findings of the workshop and the key recommendations for future research to support the development of a science of power management. This workshop would not have been possible without the hard work and diligence of the breakout group leaders and the workshop attendees. We would also like to thank the steering committee members for the additional time and effort they volunteered despite their intense schedules. And finally, a word of thanks to the National Science Foundation for sponsoring this workshop without which this report would have been impossible. Kirk W. Cameron, Virginia Tech Kirk Pruhs, University of Pittsburgh Krishna Kant, NSF SciPM Workshop Co-chairsVersion 1.0 Technical Report No. VT/CS-09-19 August 31, 2009 4 Executive Summary We believe that there is a need for a consolidated effort to establish a Science of Power Management, or comprehensive set of principles and techniques that provide practical solutions to the power issues facing the information technology community. Background There is clear consensus that one of the most important grand challenges facing humanity in the next century is to develop technologies that will allow us to continue advancement in a sustainable manner. There is increased scrutiny on the national and international stage for the United States to curb its energy use and thus carbon emissions. Towards this end, recent studies by the US EPA and Department of Energy have concluded that in particular more effort is needed to curb the power consumption of data centers. With the recent election of Barack Obama, the US is more likely to sign a version of the Kyoto treaty that commits the US to reduce emissions further. Currently IT devices consume about as much energy and produce about as much carbon dioxide as the airline industry. However, because use of IT technology is still growing exponentially (centralized deployments of enterprise volume servers in data centers are growing 12% annually), and because energy and power have not traditionally been first order design constraints for IT technology, improvements in the energy efficiency of IT devices will be much more dramatic, and eventually have much greater impact than in other areas of technology, such as aircraft technology. Some progress is already being made towards these goals. For example, the IT industry has formed groups such as the Green Grid and SPECpower aimed at self-regulation through establishment of best practices for energy efficient data centers. While it is important to address power management issues in every aspect of IT use, improving the energy efficiency of large data centers is a particularly critical need. If the power consumption of data centers goes unchecked, the sustainability of our national computing infrastructure is in question. These servers support the electronic infrastructure critical to enterprise use for businesses, e-commerce and the Internet. Power consumption and heat production lead to increased cost and reduced reliability in current data centers which in turn amplifies the need to build more. There has then been a dramatic growth recently in the scope and diversity of