This book constitutes the thoroughly refereed post-proceedings of the Second International Workshop on Power-Aware Computer Systems, PACS 2002, held in Cambridge, MA, USA, in February 2002. The 13 revised full papers presented were carefully selected for inclusion in the book during two rounds of reviewing and revision. The papers are organized in topical sections on power-aware architecture and microarchitecture, power-aware real-time systems, power modeling and monitoring, and power-aware operating systems and compilers.

The phenomenal increases in computer system performance in recent years have been accompanied by a commensurate increase in power and energy dissipation. The latter has directly resulted in demand for expensive packaging and cooling technology, an increase in product cost, and a decrease in product reliability in all segments of the computing market. Moreover, the higher power/energy dissipation has signi cantly reduced battery life in portable systems. While - stem designers have traditionally relied on circuit-level techniques to reduce - wer/energy, there is a growing need to address power/energy dissipation at all levels of the computer system. We are pleased to welcome you to the proceedings of the Power-Aware C- puter Systems (PACS 2000) workshop. PACS 2000 was the rst workshop in its series and its aim was to bring together experts from academia and industry to address power-/energy-awareness at all levels of computer systems. In these p- ceedings, we bring you several excellent research contributions spanning a wide spectrum of areas in power-aware systems, from application all the way to c- pilers and microarchitecture, and to power/performance estimating models and tools. We have grouped the contributions into the following speci c categories: (1) power-aware microarchitectural/circuit techniques, (2) application/compiler power optimizations, (3) exploiting opportunity for power optimization in - struction scheduling and cache memories, and (4) power/performance models and tools.

With the advent of portable and autonomous computing systems, power con sumption has emerged as a focal point in many research projects, commercial systems and DoD platforms. One current research initiative, which drew much attention to this area, is the Power Aware Computing and Communications (PAC/C) program sponsored by DARPA. Many of the chapters in this book include results from work that have been supported by the PACIC program. The performance of computer systems has been tremendously improving while the size and weight of such systems has been constantly shrinking. The capacities of batteries relative to their sizes and weights has been also improv ing but at a rate which is much slower than the rate of improvement in computer performance and the rate of shrinking in computer sizes. The relation between the power consumption of a computer system and it performance and size is a complex one which is very much dependent on the specific system and the technology used to build that system. We do not need a complex argument, however, to be convinced that energy and power, which is the rate of energy consumption, are becoming critical components in computer systems in gen eral, and portable and autonomous systems, in particular. Most of the early research on power consumption in computer systems ad dressed the issue of minimizing power in a given platform, which usually translates into minimizing energy consumption, and thus, longer battery life.

Implementing energy-efficient CPUs and peripherals as well as reducing resource consumption have become emerging trends in computing. As computers increase in speed and power, their energy issues become more and more prevalent. The need to develop and promote environmentally friendly computer technologies and systems has also come to the forefront

This book provides basic and fundamental knowledge of various aspects of energy-aware computing at the component, software, and system level. It provides a broad range of topics dealing with power-, energy-, and temperature-related research areas for individuals from industry and academia.

"This book covers a great variety of topics such as materials, environment, electronics, and computing, offering a vital source of information detailing the latest architectures, frameworks, methodologies, and research on energy-aware systems and networking for sustainable initiatives"--

The energy consumption issue in distributed computing systems raises various monetary, environmental and system performance concerns. Electricity consumption in the US doubled from 2000 to 2005. From a financial and environmental standpoint, reducing the consumption of electricity is important, yet these reforms must not lead to performance degradation of the computing systems. These contradicting constraints create a suite of complex problems that need to be resolved in order to lead to 'greener' distributed computing systems. This book brings together a group of outstanding researchers that investigate the different facets of green and energy efficient distributed computing. Key features: One of the first books of its kind Features latest research findings on emerging topics by well-known scientists Valuable research for grad students, postdocs, and researchers Research will greatly feed into other technologies and application domains

This lecture provides an introduction to the problem of managing the energy demand of mobile devices. Reducing energy consumption, primarily with the goal of extending the lifetime of battery-powered devices, has emerged as a fundamental challenge in mobile computing and wireless communication. The focus of this lecture is on a systems approach where software techniques exploit state-of-the-art architectural features rather than relying only upon advances in lower-power circuitry or the slow improvements in battery technology to solve the problem. Fortunately, there are many opportunities to innovate on managing energy demand at the higher levels of a mobile system. Increasingly, device components offer low power modes that enable software to directly affect the energy consumption of the system. The challenge is to design resource management policies to effectively use these capabilities. The lecture begins by providing the necessary foundations, including basic energy terminology and widely accepted metrics, system models of how power is consumed by a device, and measurement methods and tools available for experimental evaluation. For components that offer low power modes, management policies are considered that address the questions of when to power down to a lower power state and when to power back up to a higher power state. These policies rely on detecting periods when the device is idle as well as techniques for modifying the access patterns of a workload to increase opportunities for power state transitions. For processors with frequency and voltage scaling capabilities, dynamic scheduling policies are developed that determine points during execution when those settings can be changed without harming quality of service constraints. The interactions and tradeoffs among the power management policies of multiple devices are discussed. We explore how the effective power management on one component of a system may have either a positive or negative impact on overall energy consumption or on the design of policies for another component. The important role that application-level involvement may play in energy management is described, with several examples of cross-layer cooperation. Application program interfaces (APIs) that provide information flow across the application-OS boundary are valuable tools in encouraging development of energy-aware applications. Finally, we summarize the key lessons of this lecture and discuss future directions in managing energy demand.

The ability of parallel computing to process large data sets and handle time-consuming operations has resulted in unprecedented advances in biological and scientific computing, modeling, and simulations. Exploring these recent developments, the Handbook of Parallel Computing: Models, Algorithms, and Applications provides comprehensive coverage on a