John Leroy Hennessy (born September 22, 1952) is an American computer scientist,

academician An academician is a full member of an artistic, literary, engineering, or scientific academy. In many countries, it is an honorific title used to denote a full member of an academy that has a strong influence on national scientific life. In syst ...

and businessman who serves as Chairman of

Alphabet Inc. Alphabet Inc. is an American multinational technology conglomerate holding company headquartered in Mountain View, California. It was created through a restructuring of Google on October 2, 2015, and became the parent company of Google and se ...

Hennessy is one of the founders of MIPS Computer Systems Inc. as well as

Atheros Qualcomm Atheros is a developer of semiconductor Integrated circuit, chips for Computer network, network communications, particularly wireless chipsets. Founded under the name T-Span Systems in 1998 by experts in signal processing and VLSI desig ...

and served as the tenth President of

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is conside ...

. Hennessy announced that he would step down in the summer of 2016. He was succeeded as President by Marc Tessier-Lavigne.

Marc Andreessen Marc Lowell Andreessen ( ; born July 9, 1971) is an American entrepreneur, investor, and software engineer. He is the co-author of Mosaic, the first widely used web browser; co-founder of Netscape; and co-founder and general partner of Silico ...

called him "the godfather of

Silicon Valley Silicon Valley is a region in Northern California that serves as a global center for high technology and innovation. Located in the southern part of the San Francisco Bay Area, it corresponds roughly to the geographical areas San Mateo Cou ...

." Along with David Patterson, Hennessy was a recipient of the 2017

Turing Award The ACM A. M. Turing Award is an annual prize given by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to computer science. It is generally recognized as the highest distinction in compu ...

for their work in developing the

reduced instruction set computer In computer engineering, a reduced instruction set computer (RISC) is a computer designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set comp ...

(RISC) architecture, which is now used in 99% of new computer chips.

Early life and education

Hennessy was raised in

Huntington, New York The Town of Huntington is one of ten towns in Suffolk County, New York. Founded in 1653, it is located on the north shore of Long Island in northwestern Suffolk County, with Long Island Sound to its north and Nassau County adjacent to the west. ...

, as one of six children. His father was an aerospace engineer and his mother was a teacher before raising her children. He earned his

bachelor's degree A bachelor's degree (from Middle Latin ''baccalaureus'') or baccalaureate (from Modern Latin ''baccalaureatus'') is an undergraduate academic degree awarded by colleges and universities upon completion of a course of study lasting three to si ...

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

from

Villanova University Villanova University is a private Roman Catholic research university in Villanova, Pennsylvania. It was founded by the Augustinians in 1842 and named after Saint Thomas of Villanova. The university is the oldest Catholic university in Pennsy ...

, and his

master's degree A master's degree (from Latin ) is an academic degree awarded by universities or colleges upon completion of a course of study demonstrating mastery or a high-order overview of a specific field of study or area of professional practice.

and

Doctor of Philosophy A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

from

Stony Brook University Stony Brook University (SBU), officially the State University of New York at Stony Brook, is a public research university in Stony Brook, New York. Along with the University at Buffalo, it is one of the State University of New York system' ...

Career and research

Hennessy became a Stanford faculty member in 1977. In 1981, he began the MIPS project to investigate

RISC In computer engineering, a reduced instruction set computer (RISC) is a computer designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set comp ...

processor Processor may refer to: Computing Hardware * Processor (computing) **Central processing unit (CPU), the hardware within a computer that executes a program *** Microprocessor, a central processing unit contained on a single integrated circuit (I ...

s, and in 1984, he used his sabbatical year to found MIPS Computer Systems Inc. to commercialize the technology developed by his research. In 1987, he became the Willard and Inez Kerr Bell Endowed Professor of Electrical Engineering and Computer Science. Hennessy served as director of Stanford's Computer System Laboratory (1989–93), a research center run by Stanford's Electrical Engineering and Computer Science departments. He was chair of the Department of Computer Science (1994–96) and Dean of the School of Engineering (1996–99). In 1999, Stanford President

Gerhard Casper Gerhard Casper (born December 25, 1937) is a political scientist who is a former president of Stanford University from 1992 to 2000, a former Dean of the University of Chicago Law School from 1979 to 1987, and a former provost of the University o ...

appointed Hennessy to succeed

Condoleezza Rice Condoleezza Rice ( ; born November 14, 1954) is an American diplomat and political scientist who is the current director of the Hoover Institution at Stanford University. A member of the Republican Party, she previously served as the 66th Un ...

as Provost of Stanford University. When Casper stepped down to focus on teaching in 2000, the Stanford Board of Trustees named Hennessy to succeed Casper as president. In 2008, Hennessy earned a salary of $1,091,589 ($702,771 base salary, $259,592 deferred benefits, $129,226 non-tax benefits), the 23rd highest among all American university presidents. Hennessy has served as a board member of

Google Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...

(later

Cisco Systems Cisco Systems, Inc., commonly known as Cisco, is an American-based multinational digital communications technology conglomerate corporation headquartered in San Jose, California. Cisco develops, manufactures, and sells networking hardware, ...

, Atheros Communications, and the

Gordon and Betty Moore Foundation The Gordon and Betty Moore Foundation is an American foundation established by Intel co-founder Gordon E. Moore and his wife Betty I. Moore in September 2000 to support scientific discovery, environmental conservation, patient care improvements a ...

. He was elected to the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

in 2008. On October 14, 2010, Hennessy was presented a

khata A ''khata'' or ''khatag'', ''dhar'', Mongolian: mn, хадаг, label=none, , or ; ne, खतक ; . is a traditional ceremonial scarf in Tibetan Buddhism and in tengerism. It originated in Tibetan culture and is common in cultures and cou ...

by the

14th Dalai Lama The 14th Dalai Lama (spiritual name Jetsun Jamphel Ngawang Lobsang Yeshe Tenzin Gyatso, known as Tenzin Gyatso (Tibetan: བསྟན་འཛིན་རྒྱ་མཚོ་, Wylie: ''bsTan-'dzin rgya-mtsho''); né Lhamo Thondup), known as ...

before the latter addressed

Maples Pavilion Maples Pavilion is a 7,392-seat multi-purpose arena on the campus of Stanford University in Stanford, California. Opened in 1969, Maples underwent a $30 million renovation in March 2004 and reopened ahead of schedule, in time for conference play ...

. In December 2010, Hennessy coauthored an editorial with

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of highe ...

President

Drew Gilpin Faust Catharine Drew Gilpin Faust (born September 18, 1947) is an American historian and was the 28th president of Harvard University, the first woman to serve in that role. She was Harvard's first president since 1672 without an undergraduate or gradu ...

urging the passage of the

DREAM Act The Development, Relief, and Education for Alien Minors Act, known as the DREAM Act, is a United States legislative proposal to grant temporary conditional residency, with the right to work, to illegal immigrants who entered the United States a ...

; the legislation did not pass the

111th United States Congress The 111th United States Congress was a meeting of the legislative branch of the United States federal government from January 3, 2009, until January 3, 2011. It began during the last weeks of the George W. Bush administration, with th ...

. In 2013, Hennessy became a judge for the inaugural

Queen Elizabeth Prize for Engineering The Queen Elizabeth Prize for Engineering, also known as the QEPrize, is a global prize for engineering and innovation. The prize was launched in 2012 by a cross-party group consisting of David Cameron, Nick Clegg, and Ed Miliband, then Prime ...

. He has remained on the judging panel for the subsequent awards in 2015 and 2017. In June 2015, Hennessy announced that he would step down as Stanford president in summer 2016. In 2016, Hennessy co-founded the

Knight-Hennessy Scholars Knight-Hennessy Scholars is an international graduate-level scholarship program for study at Stanford University. Established in 2016, the program prepares students to take leadership roles in finding creative solutions to complex global issues. ...

program; he serves as its inaugural director. The program has a $750 million endowment to fully fund graduate students at Stanford for up to three years. The inaugural class of 51 scholars from 21 countries arrived at Stanford in the fall of 2018. In February 2018, Hennessy was announced as the new Chairman of

's parent company. Hennessy has a history of strong interest and involvement in college-level computer education. He co-authored, with David Patterson, two well-known books on

computer architecture In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the ...

, ''Computer Organization and Design: the Hardware/Software Interface'' and ''Computer Architecture: A Quantitative Approach'', which introduced the

DLX The DLX (pronounced "Deluxe") is a RISC processor architecture designed by John L. Hennessy and David A. Patterson, the principal designers of the Stanford MIPS and the Berkeley RISC designs (respectively), the two benchmark examples of RISC des ...

RISC architecture. They have been widely used as

textbook A textbook is a book containing a comprehensive compilation of content in a branch of study with the intention of explaining it. Textbooks are produced to meet the needs of educators, usually at educational institutions. Schoolbooks are textbook ...

s for graduate and undergraduate courses since 1990. Hennessy also contributed to updating

Donald Knuth Donald Ervin Knuth ( ; born January 10, 1938) is an American computer scientist, mathematician, and professor emeritus at Stanford University. He is the 1974 recipient of the ACM Turing Award, informally considered the Nobel Prize of computer sc ...

's MIX processor to the

MMIX MMIX (pronounced ''em-mix'') is a 64-bit reduced instruction set computing (RISC) architecture designed by Donald Knuth, with significant contributions by John L. Hennessy (who contributed to the design of the MIPS architecture) and Richard L ...

. Both are model computers used in Knuth's classic series, ''

The Art of Computer Programming ''The Art of Computer Programming'' (''TAOCP'') is a comprehensive monograph written by the computer scientist Donald Knuth presenting programming algorithms and their analysis. Volumes 1–5 are intended to represent the central core of com ...

''. MMIX is Knuth's DLX equivalent.

Awards and honors

National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of ...

: 1992 For innovations in computer architecture and software techniques for reduced instruction set computers (RISC), and for quantitative evaluation methods for modern computer architectures. * * * * * * * * * *

BBVA Foundation Frontiers of Knowledge Award The BBVA Foundation Frontiers of Knowledge Awards () are an international award programme recognizing significant contributions in the areas of scientific research and cultural creation. The categories that make up the Frontiers of Knowledge Awards ...

2020 in Information and Communication Technologies. * In 2020, he received from the UC Berkeley Academic Senate the Clark Kerr Award for distinguished leadership in higher education. * In 2022, he was awarded the

Charles Stark Draper Prize The U.S. National Academy of Engineering annually awards the Draper Prize, which is given for the advancement of engineering and the education of the public about engineering. It is one of three prizes that constitute the "Nobel Prizes of Enginee ...

by the

alongside

Steve Furber Stephen Byram Furber (born 21 March 1953) is a British computer scientist, mathematician and hardware engineer, currently the ICL Professor of Computer Engineering in the Department of Computer Science at the University of Manchester, UK. A ...

, David Patterson and

Sophie Wilson Sophie Mary Wilson (born Roger Wilson; June 1957) is an English computer scientist, who helped design the BBC Micro and ARM architecture. Wilson first designed a microcomputer during a break from studies at Selwyn College, Cambridge. She ...

for contributions to the invention, development, and implementation of

(RISC) chips.

Selected publications

* Computer Architecture: A Quantitative Approach * * *

Personal life

Hennessy is married to Andrea Berti who he met in high school.

References

{{DEFAULTSORT:Hennessy, John L. American computer scientists Computer designers 1952 births Living people American corporate directors Directors of Alphabet Inc. Fellows of the Association for Computing Machinery Members of the United States National Academy of Engineering Members of the United States National Academy of Sciences Presidents of Stanford University Provosts of Stanford University Seymour Cray Computer Engineering Award recipients Stanford University School of Engineering faculty Stanford University Department of Electrical Engineering faculty Scientists from California Villanova University alumni Stony Brook University alumni MIPS Technologies 20th-century American scientists 21st-century American scientists Fellow Members of the IEEE Fellows of the American Academy of Arts and Sciences Turing Award laureates American university and college faculty deans Silicon Valley people IEEE Medal of Honor recipients