John L. Hennessy won the 2017 Turing Award along with David Patterson, his collaborator at the University of California, Berkeley. (Image credit: L.A. Cicero)

Former Stanford University President John Hennessy has been awarded the 2017 ACM A.M. Turing Award for his work pioneering an approach to computer architecture and its impact on the microprocessor industry. He shares the prize with long-time collaborator David Patterson, a professor emeritus of computer science at the University of California, Berkeley.

Today, 99 percent of the more than 16 billion microprocessors produced annually are based on faster, lower power approaches developed in the 1980s by Hennessy and Patterson.

“It is exciting and gratifying to have the Turing Prize recognize the profound impact of John Hennessy’s and David Patterson’s fundamental research, which has revolutionized an entire industry over a period of decades,” said Stanford President Marc Tessier-Lavigne. “It’s also a joyful moment to celebrate a landmark research partnership across the San Francisco Bay.”

The Turing Award, awarded by the Association for Computing Machinery, carries a $1 million prize. It is named for Alan M. Turing, the British mathematician who articulated the mathematical foundation and limits of computing. Hennessy and Patterson will formally receive their prize at a banquet on June 23 in San Francisco.

“The Turing Award is truly a capstone to my career as a computer scientist,” said Hennessy, who is now the Shriram Family Director of the Knight-Hennessy Scholars program. “I am honored to join many Stanford colleagues, including Don Knuth, Ed Feigenbaum, John McCarthy, and Martin Hellman, who have been previous winners. This award also celebrates the collaborations, both informal and formal, between Dave Patterson and me that have gone on for about 30 years.”

Transformational technology

In 1981, when Hennessy initiated a collaboration at Stanford called the MIPS project to develop his ideas, the prevailing approach to computer architecture involved complex sets of instructions to carry out any given task. Hennessy and Patterson both felt that computing could be made more efficient with simpler instruction sets that could be completed in less time.

Eventually, their approach came to be known as a reduced instruction set computer (RISC) architecture. RISC processors involved significantly fewer transistors. Their simpler design led to faster speeds, lower costs and shorter design times.

“The RISC designs pioneered by John Hennessy and Dave Patterson changed the trajectory of computer technology, making possible today’s fast, efficient and ubiquitous devices,” said Jennifer Widom, dean of the School of Engineering. “Their approach inspired the next generations of technology, including those being developed today.”

In 1984, Hennessy used his sabbatical year to found MIPS Computer Systems Inc. to commercialize the technology developed by his research. Around the same time, Sun Microsystems began producing their SPARC workstations based on Patterson’s work.

The biggest change with the advent of RISC was processing speed. For the first time, RISC architectures allowed low-cost computers to overlap work from several instructions rather than handling them separately and strictly sequentially.

By the 1990s RISC designs were the foundation of workstations and servers. Today, RISC architectures underlie many of the technologies that have become part of daily life, from tablets and cell phones to household smart devices.

Lasting influence

Hennessy and Patterson’s influence has been so significant, Bill Gates, principal founder of Microsoft Corporation, said in the ACM award announcement that their contributions “have proven to be fundamental to the very foundation upon which an entire industry flourished.”

Part of the pair’s impact on the field of computing came about through the foundational book, Computer Architecture: A Quantitative Approach that reached generations of engineers and scientists. Now in its fifth edition, the book is credited with significantly increasing the pace of advances in microprocessor design.

“The most incredible thing about John is that while he was doing all these other things like founding startups, being dean of the School of Engineering, Stanford provost and then president, he was also the coauthor of the fundamental textbook on how to design computers that was read by everybody,” said Donald Knuth, professor emeritus of computer science. “That book is why he’s influenced everything and all the computers we have now.”