John L. Hennessy

Hennessy was raised in Huntington, New York, as one of six children. His father was an aerospace engineer, and his mother was a teacher before raising her children. He is of Irish-Catholic descent, with some of his ancestors arriving in America during the potato famine in the 19th century.

He earned his bachelor's degree in electrical engineering from Villanova University, and his master's degree and Doctor of Philosophy in computer science from Stony Brook University.

Hennessy became a Stanford faculty member in 1977. In 1981, he began the MIPS project to investigate RISC processors, following preliminary investigations at Berkeley by David A. Patterson. On 1984, he used his sabbatical year to found MIPS Computer Systems Inc. to commercialize the technology developed by his research. Returning to Stanford, he became the Willard and Inez Kerr Bell Endowed Professor of Electrical Engineering and Computer Science in 1987. In 1988, Hennessy and Patterson began a three-year effort to write the first edition Computer Architecture: A Quantitative Approach, which described RISC instruction sets and cost-performance tradeoffs.

As a full Stanford professor, Hennessy took administrative roles of growing breadth. He was 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 appointed Hennessy to succeed Condoleezza Rice 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's compensation exceeded $1 million, the 23rd highest among all American university presidents.

Hennessy has been a board member of Google (later Alphabet Inc.), Cisco Systems, Atheros Communications, and the Gordon and Betty Moore Foundation. He was elected to the American Philosophical Society in 2008.

On October 14, 2010, Hennessy was presented a khata by the 14th Dalai Lama before the latter addressed Maples Pavilion.

In December 2010, Hennessy coauthored an editorial with Harvard University President Drew Gilpin Faust urging the passage of the DREAM Act; the legislation did not pass the 111th United States Congress.

In 2013, Hennessy became a judge for the inaugural Queen Elizabeth Prize for Engineering. 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. He was succeeded as president by Marc Tessier-Lavigne.

In 2016, Hennessy co-founded the Knight-Hennessy Scholars 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 Alphabet Inc., Google's parent company. That same year, his book Leading Matters: Lessons from My Journey was published by Stanford University Press.

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, Computer Organization and Design: the Hardware/Software Interface and Computer Architecture: A Quantitative Approach, which introduced the DLX RISC architecture. They have been widely used as textbooks for graduate and undergraduate courses since 1990.

Hennessy also contributed to updating Donald Knuth's MIX processor to the MMIX. Both are model computers used in Knuth's classic series, The Art of Computer Programming. MMIX is Knuth's DLX equivalent.

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