# John L. Hennessy

> American computer scientist (born 1952)

**Wikidata**: [Q92854](https://www.wikidata.org/wiki/Q92854)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/John_L._Hennessy)  
**Source**: https://4ort.xyz/entity/john-l-hennessy

## Summary
John L. Hennessy is an American computer scientist, academic, and entrepreneur known for pioneering reduced instruction set computing (RISC) architecture. He served as president of Stanford University from 2000 to 2016 and co-founded MIPS Computer Systems. Hennessy received the 2017 Turing Award for his contributions to computer architecture.

## Biography
- Born: September 22, 1952 in Huntington
- Nationality: United States
- Education: Ph.D. from Stony Brook University; education at Villanova University
- Known for: Pioneering RISC architecture, co-founding MIPS Computer Systems, serving as Stanford University president
- Employer(s): Stanford University (professor, president, provost), Alphabet Inc. (board member), Knight-Hennessy Scholars (director)
- Field(s): Computer science, electrical engineering, computer architecture, information technology, informatics

## Contributions
John L. Hennessy co-developed RISC (Reduced Instruction Set Computing) architecture in the 1980s, revolutionizing computer processor design by simplifying instructions to improve performance and efficiency. This work led to the founding of MIPS Computer Systems in 1984, which commercialized RISC technology and became influential in both academic and commercial computing. At Stanford University, Hennessy served as chair of the Computer Science Department, dean of the School of Engineering, provost, and president from 2000 to 2016. He co-authored the widely-used textbook "Computer Architecture: A Quantitative Approach" and has supervised numerous doctoral students who became leaders in computer science. Hennessy also serves on the board of Alphabet Inc. and directs the Knight-Hennessy Scholars program at Stanford.

## FAQs
### Q: What is John L. Hennessy famous for?
A: John L. Hennessy is famous for co-developing RISC architecture, serving as Stanford University president, and receiving the 2017 Turing Award for his contributions to computer architecture.

### Q: What companies did John L. Hennessy found?
A: John L. Hennessy co-founded MIPS Computer Systems in 1984, a company that commercialized RISC processor technology.

### Q: What awards has John L. Hennessy received?
A: Hennessy has received the Turing Award (2017), IEEE Medal of Honor (2012), IEEE John von Neumann Medal (2000), and is a Fellow of ACM, IEEE, and member of multiple national academies.

## Why They Matter
John L. Hennessy fundamentally transformed computer architecture through RISC, enabling the development of faster, more efficient processors that power modern computing devices. His work made high-performance computing accessible to a broader range of applications and influenced processor design across the industry. As Stanford's president, he expanded the university's global impact and launched initiatives in online education. His textbook has educated generations of computer scientists, and his mentorship has shaped numerous leaders in technology. Without Hennessy's contributions, modern mobile devices, servers, and many computing applications would be significantly less capable, and the field of computer architecture would have evolved along different lines.

## Notable For
- Co-developed RISC architecture, revolutionizing processor design
- Received the 2017 Turing Award, computing's highest honor
- Served as 10th president of Stanford University (2000-2016)
- Co-founded MIPS Computer Systems, pioneering commercial RISC processors
- Supervised over 40 doctoral students who became leaders in computer science

## Body
### RISC Architecture Development
Hennessy's work on RISC architecture in the 1980s challenged conventional wisdom about processor design. Along with David Patterson, he demonstrated that simplified instruction sets could achieve higher performance than complex instruction set computers (CISC). This research, published in the seminal paper "A Case for the Reduced Instruction Set Computer" (1980), showed that compilers could handle complexity more efficiently than hardware, leading to faster and more energy-efficient processors.

### Academic Leadership
At Stanford, Hennessy held multiple leadership positions: chair of Computer Science Department, dean of Engineering, provost, and president. During his presidency, he oversaw significant growth in research funding, launched Stanford's first online high school, and expanded international programs. He also initiated the Knight-Hennessy Scholars program, a fully-funded graduate scholarship for global leaders.

### Industry Impact
Beyond academia, Hennessy co-founded MIPS Computer Systems, which developed one of the first commercial RISC processors. MIPS technology influenced processor design at companies like Silicon Graphics, Nintendo, and various embedded systems manufacturers. His work continues to impact modern processor design in mobile devices, servers, and specialized computing applications.

### Publications and Education
Hennessy co-authored "Computer Architecture: A Quantitative Approach" with David Patterson, now in its sixth edition and considered the definitive textbook in the field. This book introduced quantitative methods for evaluating computer architecture and has educated generations of computer scientists and engineers worldwide.

### Mentorship and Legacy
As an academic advisor, Hennessy supervised over 40 doctoral students, including notable computer scientists like Anant Agarwal, Lawrence Paulson, and Josep Torrellas. Many of his students have become professors, entrepreneurs, and leaders in technology companies, extending his influence throughout the computing field.

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## References

1. Czech National Authority Database
2. BnF authorities
3. [Source](https://profiles.stanford.edu/john-hennessy)
4. [proxy statement](https://www.sec.gov/Archives/edgar/data/1652044/000130817922000262/lgoog2022_def14a.htm)
5. [Source](http://hennessy.stanford.edu/biography/)
6. Integrated Authority File
7. [Source](http://www.computerhistory.org/collections/catalog/102658153)
8. [Source](https://www.ieee.org/content/dam/ieee-org/ieee/web/org/about/awards/recipients/moh-rl.pdf)
9. [Source](https://www.ieee.org/content/dam/ieee-org/ieee/web/org/about/awards/piore_rl.pdf)
10. [Source](https://awards.acm.org/eckert-mauchly/award-recipients)
11. [Source](https://www.acm.org/media-center/2018/march/turing-award-2017)
12. [Source](https://www.upc.edu/ca/la-upc/honoris-causa)
13. [Source](https://awards.acm.org/fellows/award-recipients)
14. [Ministry of Education of the People's Republic of China](http://www.moe.gov.cn/s78/A22/xwb_left/moe_829/tnull_44386.html)
15. [Source](https://www.nae.edu/55291/DraperWinners#tabs)
16. [Source](http://www.okawa-foundation.or.jp/en/activities/prize/list.html)
17. Mathematics Genealogy Project
18. International Standard Name Identifier
19. Virtual International Authority File
20. CiNii Research
21. Freebase Data Dumps. 2013
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26. National Library of Israel Names and Subjects Authority File