Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page R1
T H E F U T U R E O F
COMPUTING PERFORMANCE
Game Over or
Next Level?
Samuel H. Fuller and Lynette I. Millett, Editors
Committee on Sustaining Growth in Computing Performance
Computer Science and Telecommunications Board
Division on Engineering and Physical Science
OCR for page R2
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001
NOTICE: The project that is the subject of this report was approved by the Gov-
erning Board of the National Research Council, whose members are drawn from
the councils of the National Academy of Sciences, the National Academy of Engi -
neering, and the Institute of Medicine. The members of the committee responsible
for the report were chosen for their special competences and with regard for
appropriate balance.
Support for this project was provided by the National Science Foundation under
award CNS-0630358. Any opinions, findings, conclusions, or recommendations
expressed in this publication are those of the authors and do not necessarily reflect
the views of the organization that provided support for the project.
International Standard Book Number-13: 978-0-309-15951-7
International Standard Book Number-10: 0-309-15951-2
Library of Congress Control Number: 2011923200
Additional copies of this report are available from
The National Academies Press
500 Fifth Street, N.W., Lockbox 285
Washington, D.C. 20055
800 624-6242
202 334-3313 (in the Washington metropolitan area)
http://www.nap.edu
Copyright 2011 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America
OCR for page R3
The National Academy of Sciences is a private, nonprofit, self-perpetuating
society of distinguished scholars engaged in scientific and engineering research,
dedicated to the furtherance of science and technology and to their use for the
general welfare. Upon the authority of the charter granted to it by the Congress
in 1863, the Academy has a mandate that requires it to advise the federal govern -
ment on scientific and technical matters. Dr. Ralph J. Cicerone is president of the
National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter
of the National Academy of Sciences, as a parallel organization of outstanding
engineers. It is autonomous in its administration and in the selection of its mem -
bers, sharing with the National Academy of Sciences the responsibility for advis -
ing the federal government. The National Academy of Engineering also sponsors
engineering programs aimed at meeting national needs, encourages education
and research, and recognizes the superior achievements of engineers. Dr. Charles
M. Vest is president of the National Academy of Engineering.
The Institute of Medicine was established in 1970 by the National Academy of
Sciences to secure the services of eminent members of appropriate professions
in the examination of policy matters pertaining to the health of the public. The
Institute acts under the responsibility given to the National Academy of Sciences
by its congressional charter to be an adviser to the federal government and, upon
its own initiative, to identify issues of medical care, research, and education.
Dr. Harvey V. Fineberg is president of the Institute of Medicine.
The National Research Council was organized by the National Academy of
Sciences in 1916 to associate the broad community of science and technology
with the Academy’s purposes of furthering knowledge and advising the federal
government. Functioning in accordance with general policies determined by the
Academy, the Council has become the principal operating agency of both the
National Academy of Sciences and the National Academy of Engineering in pro -
viding services to the government, the public, and the scientific and engineering
communities. The Council is administered jointly by both Academies and the
Institute of Medicine. Dr. Ralph J. Cicerone and Dr. Charles M. Vest are chair and
vice chair, respectively, of the National Research Council.
www.national-academies.org
OCR for page R4
OCR for page R5
COMMITTEE ON SUSTAINING GROWTH
IN COMPUTING PERFORMANCE
SAMUEL H. FULLER, Analog Devices Inc., Chair
LUIZ ANDRÉ BARROSO, Google, Inc.
ROBERT P. COLWELL, Independent Consultant
WILLIAM J. DALLY, NVIDIA Corporation and Stanford University
DAN DOBBERPUHL, P.A. Semi
PRADEEP DUBEY, Intel Corporation
MARK D. HILL, University of Wisconsin–Madison
MARK HOROWITZ, Stanford University
DAVID KIRK, NVIDIA Corporation
MONICA LAM, Stanford University
KATHRYN S. McKINLEY, University of Texas at Austin
CHARLES MOORE, Advanced Micro Devices
KATHERINE YELICK, University of California, Berkeley
Staff
LYNETTE I. MILLETT, Study Director
SHENAE BRADLEY, Senior Program Assistant
v
OCR for page R6
COMPUTER SCIENCE AND TELECOMMUNICATIONS BOARD
ROBERT F. SPROULL, Sun Labs, Chair
PRITHVIRAJ BANERJEE, Hewlett Packard Company
STEVEN M. BELLOVIN, Columbia University
WILLIAM J. DALLY, NVIDIA Corporation and Stanford University
SEYMOUR E. GOODMAN, Georgia Institute of Technology
JOHN E. KELLY, III, IBM
JON M. KLEINBERG, Cornell University
ROBERT KRAUT, Carnegie Mellon University
SUSAN LANDAU, Radcliffe Institute for Advanced Study
PETER LEE, Microsoft Corporation
DAVID LIDDLE, US Venture Partners
WILLIAM H. PRESS, University of Texas
PRABHAKAR RAGHAVAN, Yahoo! Research
DAVID E. SHAW, Columbia University
ALFRED Z. SPECTOR, Google, Inc.
JOHN SWAINSON, Silver Lake Partners
PETER SZOLOVITS, Massachusetts Institute of Technology
PETER J. WEINBERGER, Google, Inc.
ERNEST J. WILSON, University of Southern California
JON EISENBERG, Director
RENEE HAWKINS, Financial and Administrative Manager
HERBERT S. LIN, Chief Scientist
LYNETTE I. MILLETT, Senior Program Officer
EMILY ANN MEYER, Program Officer
ENITA A. WILLIAMS, Associate Program Officer
VIRGINIA BACON TALATI, Associate Program Officer
SHENAE BRADLEY, Senior Program Assistant
ERIC WHITAKER, Senior Program Assistant
For more information on CSTB, see its website at
http://www.cstb.org, write to CSTB, National Research Council,
500 Fifth Street, N.W., Washington, D.C. 20001, call (202) 334-2605,
or e-mail the CSTB at cstb@nas.edu.
vi
OCR for page R7
Preface
F
ast, inexpensive computers are now essential for nearly all human
endeavors and have been a critical factor in increasing economic
productivity, enabling new defense systems, and advancing the
frontiers of science. But less well understood is the need for ever-faster
computers at ever-lower costs. For the last half-century, computers have
been doubling in performance and capacity every couple of years. This
remarkable, continuous, exponential growth in computing performance
has resulted in an increase by a factor of over 100 per decade and more
than a million in the last 40 years. For example, the raw performance of
a 1970s supercomputer is now available in a typical modern cell phone.
That uninterrupted exponential growth in computing throughout the
lifetimes of most people has resulted in the expectation that such phenom-
enal progress, often called Moore’s law, will continue well into the future.
Indeed, societal expectations for increased technology performance con -
tinue apace and show no signs of slowing, a trend that underscores the
need to find ways to sustain exponentially increasing performance in
multiple dimensions.
The essential engine that made that exponential growth possible is
now in considerable danger. Thermal-power challenges and increasingly
expensive energy demands pose threats to the historical rate of increase in
processor performance. The implications of a dramatic slowdown in how
quickly computer performance is increasing—for our economy, our mili -
tary, our research institutions, and our way of life—are substantial. That
obstacle to continuing growth in computing performance is by now well
vii
OCR for page R8
viii PREFACE
understood by the designers of microprocessors. Their initial response
was to design multiprocessor (often referred to as multicore) chips, but
fundamental challenges in algorithm and software design limit the wide -
spread use of multicore systems.
Even as multicore hardware systems are tailored to support software
that can exploit multiple computation units, thermal constraints will con -
tinue to be a primary concern. It is estimated that data centers delivering
Internet services consume over 1.5 percent of U.S. electric power. As the
use of the Internet continues to grow and massive computing facilities
are demanding that performance keep doubling, devoting correspond-
ing increases in the nation’s electrical energy capacity to computing may
become too expensive.
We do not have new software approaches that can exploit the innova-
tive architectures, and so sustaining performance growth—and its atten-
dant benefits—presents a major challenge. The present study emerged
from discussions among members of the Computer Science and Telecom -
munications Board and was sponsored by the National Science Foun-
dation. The original statement of task for the Committee on Sustaining
Growth in Computing Performance is as follows:
This study will bring together academic and industry researchers, ap-
plication developers, and members of the user community to explore
emerging challenges to sustaining performance growth and meeting
expectations in computing across the broad spectrum of software, hard-
ware, and architecture. It will identify key problems along with promis-
ing emerging technologies and models and describe how these might fit
together over time to enable continued performance scaling. In addition,
it will focus attention on areas where there are tractable problems whose
solution would have significant payback and at the same time highlight
known solutions to challenges that already have them. The study will
outline a research, development, and educational agenda for meeting the
emerging computing needs of the 21st century.
Parallelism and related approaches in software will increase in impor-
tance as a path to achieving continued performance growth. There have
been promising developments in the use of parallel processing in some
scientific applications, Internet search and retrieval, and the processing of
visual and graphic images. This report reviews that progress and recom -
mends subjects for further research and development. Chapter 1 exam -
ines the need for high-performance computers, and computers that are
increasingly higher-performing, in a variety of sectors of society. The
need may be intuitively obvious to some readers but is included here to
be explicit about the need for continued performance growth. Chapter 2
examines the aspects of “performance” in depth. Often used as short-
hand for speed, performance is actually a much more multidimensional
OCR for page R9
ix
PREFACE
concept. (Appendix A provides a brief history of computing performance
as a complement to Chapter 2.) Chapter 3 delves into the fundamen -
tal reasons why single-processor performance has stopped its dramatic,
exponential growth and why this is a fundamental change rather than a
temporary nuisance. Chapter 4 addresses the fundamental challenge now
facing the computer science and engineering community: how to exploit
parallelism in software and hardware. Chapter 5 outlines the committee’s
recommended research, practice, and education agenda to meet those
challenges.
This report represents the cooperative effort of many people. The
members of the study committee, after substantial discussions, drafted
and worked though several revisions of the report. We particularly appre-
ciate the insights and perspectives provided by the following experts who
briefed the committee:
Jeff Dean, Google,
Robert Doering, Texas Instruments,
Michael Foster, National Science Foundation,
Garth Gibson, Carnegie Mellon University,
Wen-Mei Hwu, University of Illinois at Urbana-Champaign,
Bruce Jacob, University of Maryland,
Jim Larus, Microsoft,
Charles Leiserson, Massachusetts Institute of Technology,
Trevor Mudge, University of Michigan,
Daniel Reed, Microsoft,
Phillip Rosedale, Linden Lab,
Vivek Sarkar, Rice University,
Kevin Skadron, University of Virginia,
Tim Sweeny, Epic Games, and
Tom Williams, Synopsys.
The committee also thanks the reviewers who provided many percep-
tive comments that helped to improve the content of the report materi -
ally. The committee thanks Michael Marty, who worked with committee
member Mark Hill to update some of the graphs, and Paul S. Diette of the
Diette Group, who assisted in refining the images. The committee appreci-
ates the financial support provided by the National Science Foundation.
The committee also gratefully acknowledges the assistance of members
of the National Research Council staff. Lynette Millett, our study direc -
tor, ably served the critical roles of study organizer, report editor, and
review coordinator. Jon Eisenberg provided many valuable suggestions
that improved the quality of the final report.
It is difficult to overstate the importance of ever-more-capable com-
OCR for page R10
x PREFACE
puters to the U.S. industrial and social infrastructure, economy, and
national security. The United States cannot afford to let this growth engine
stall out, and a concerted effort is needed to sustain it. Several centers
for parallel computing have already been established in leading research
universities. Those centers are a good start, and additional, strong actions
are required in many subdisciplines of computer science and computer
engineering. Our major goal for this study is to help to identify the actions
and opportunities that will prove most fruitful.
Samuel H. Fuller, Chair
Committee on Sustaining Growth
in Computing Performance
OCR for page R11
Acknowledgment of Reviewers
T
his report has been reviewed in draft form by individuals chosen
for their diverse perspectives and technical expertise, in accordance
with procedures approved by the National Research Council’s
(NRC’s) Report Review Committee. The purpose of this independent
review is to provide candid and critical comments that will assist the
institution in making its published report as sound as possible and to
ensure that the report meets institutional standards for objectivity, evi-
dence, and responsiveness to the study charge. The review comments
and draft manuscript remain confidential to protect the integrity of the
deliberative process. We wish to thank the following individuals for their
review of this report:
Tilak Agerwala, IBM Research,
David Ceperley, University of Illinois,
Robert Dennard, IBM Research,
Robert Doering, Texas Instruments, Inc.,
Urs Hölzle, Google, Inc.,
Norm Jouppi, Hewlett-Packard Laboratories,
Kevin Kahn, Intel Corporation,
James Kajiya, Microsoft Corporation
Randy Katz, University of California, Berkeley,
Barbara Liskov, Massachusetts Institute of Technology,
Keshav Pingali, University of Texas, Austin,
James Plummer, Stanford University, and
Vivek Sarkar, Rice University.
xi
OCR for page R12
xii ACKNOWLEDGMENTS
Although the reviewers listed above have provided many construc-
tive comments and suggestions, they were not asked to endorse the con-
clusions or recommendations, nor did they see the final draft of the report
before its release. The review of this report was overseen by Butler Lamp -
son, Microsoft Corporation. Appointed by the National Research Council,
he was responsible for making certain that an independent examination
of this report was carried out in accordance with institutional procedures
and that all review comments were carefully considered. Responsibility
for the final content of this report rests entirely with the authoring com-
mittee and the institution.
OCR for page R13
Contents
ABSTRACT 1
SUMMARY 5
1 THE NEED FOR CONTINUED PERFORMANCE GROWTH 21
Why Faster Computers Are Important, 22
The Importance of Computing Performance for the Sciences, 29
The Importance of Computing Performance for Defense and
National Security, 36
The Importance of Computing Performance for Consumer
Needs and Applications, 44
The Importance of Computing Performance for Enterprise
Productivity, 47
2 WHAT IS COMPUTER PERFORMANCE? 53
Why Performance Matters, 58
Performance as Measured by Raw Computation, 59
Computation and Communication’s Effects on Performance, 62
Technology Advances and the History of Computer Performance, 65
Assessing Performance with Benchmarks, 68
The Interplay of Software and Performance, 70
The Economics of Computer Performance, 75
xiii
OCR for page R14
xiv CONTENTS
3 P
OWER IS NOW LIMITING GROWTH IN COMPUTING 80
PERFORMANCE
Basic Technology Scaling, 83
Classic CMOS Scaling, 84
How CMOS-Processor Performance Improved Exponentially,
and Then Slowed, 87
How Chip Multiprocessors Allow Some Continued
Performance-Scaling, 90
Problems in Scaling Nanometer Devices, 94
Advanced Technology Options, 97
Application-Specific Integrated Circuits, 100
Bibliography, 103
4 THE END OF PROGRAMMING AS WE KNOW IT 105
Moore’s Bounty: Software Abstraction, 106
Software Implications of Parallelism, 110
The Challenges of Parallelism, 116
The State of the Art of Parallel Programming, 119
Parallel-Programming Systems and the Parallel
Software “Stack,” 127
Meeting the Challenges of Parallelism, 130
5 R
ESEARCH, PRACTICE, AND EDUCATION TO MEET 132
TOMORROW’S PERFORMANCE NEEDS
Systems Research and Practice, 133
Parallel-Programming Models and Education, 146
Game Over or Next Level? 150
APPENDIXES
A A History of Computer Performance 155
B Biographies of Committee Members and Staff 160
C eprint of Gordon E. Moore’s “Cramming More Components
R
onto Integrated Circuits” 169
D eprint of Robert H. Dennard’s “Design of Ion-Implanted
R
MOSFET’s with Very Small Physical Dimensions” 174
