William James Dally (born August 17, 1960) is an American computer scientist and educator. He currently serves as the chief scientist and senior vice president at Nvidia. He previously worked as a professor of Electrical Engineering and Computer Science at Stanford University and MIT. Since 2021, he has been a member of the President's Council of Advisors on Science and Technology (PCAST).

Microelectronics

He created several methods used in modern networks that connect computers, such as techniques to prevent traffic jams in data flow, a way to send data quickly through networks, methods to retry sending data if there is a problem, virtual channels, routing that adjusts based on network conditions, and routers that can handle many connections. He also created effective methods for communication, coordination, and labeling in computers that work together, including systems that use messages to control tasks and fast ways to assign addresses to computer components. He developed several specialized computers for processing data streams, starting in 1995, including Imagine, used for graphics, signals, and images, and Merrimac, used for scientific calculations.

He has written more than 200 research papers, as well as textbooks titled Digital Systems Engineering with John Poulton and Principles and Practices of Interconnection Networks with Brian Towles. He was an inventor or co-inventor on over 70 patents that have been approved.

Career

Dally earned a bachelor's degree in electrical engineering from Virginia Tech. While working at Bell Telephone Laboratories, he helped design the Bellmac 32, an early 32-bit microprocessor. He also earned a master's degree in electrical engineering from Stanford University in 1981. From 1983 to 1986, he studied at the California Institute of Technology (Caltech), where he completed a Ph.D. in computer science in 1986. At Caltech, he designed the MOSSIM simulation engine and an integrated circuit for routing. He was part of the group that started Stac Electronics in 1983.

From 1986 to 1997, he taught at MIT, where he and his team created the J–Machine and the M–Machine, parallel computers that focus on efficient communication and synchronization. During his time at MIT, he worked on the design of the Cray T3D and Cray T3E supercomputers.

In 1997, he joined Stanford University as a faculty member. He became the Willard R. and Inez Kerr Bell Professor in the School of Engineering and led the computer science department from 2005 to 2009. He is currently an Adjunct Professor at Stanford.

Dally worked with Cray Research starting in 1989. He designed Internet routers at Avici Systems from 1997 onward. He was chief technical officer at Velio Communications from 1999 until the company was acquired by LSI Logic in 2003. He was also the founder and chairman of Stream Processors, Inc., until the company closed.

In 2002, he was elected a Fellow of the Association for Computing Machinery and a Fellow of the IEEE. In 2000, he received the ACM/SIGARCH Maurice Wilkes Award. In 2004, he received the Seymour Cray Computer Science and Engineering Award. In 2006, he received the IEEE Computer Society Charles Babbage Award. In 2007, he was elected to the American Academy of Arts and Sciences.

In 2009, he became chief scientist at NVIDIA. He worked full-time at NVIDIA while overseeing about 12 graduate students at Stanford. He is currently chief scientist and senior vice president of NVIDIA Research.

At NVIDIA, Dally helped develop optical interconnects for GPUs and computing systems using micro ring modulators that use multiple wavelengths. These systems may improve the speed and efficiency of data centers used for artificial intelligence.

In 2009, he was elected to the National Academy of Engineering for his work on high-performance interconnect networks and parallel computer designs.

In 2010, he received the ACM/IEEE Eckert–Mauchly Award for his contributions to the design of interconnection networks and parallel computers.

In 2025, he was awarded the Queen Elizabeth Prize for Engineering, shared with Yoshua Bengio, Geoffrey E. Hinton, John Hopfield, Yann LeCun, Jen-Hsun Huang, and Fei-Fei Li.

Personal life

Dally is married and has three children. In 1992, he was flying a Cessna 210 from Hanscom Field, Massachusetts, to Farmingdale, New York, during poor weather conditions. The plane had an oil problem, which forced him to make an emergency landing in the Long Island Sound. He was rescued by a sailboat after the landing.

Works

Authored by William J. Dally and Curtis Harting in 2012. Published by Cambridge University Press. ISBN 978-0-521-19950-6.
Authored by William J. Dally and Brian Towles in 2004. Published by Elsevier. ISBN 978-0-12-200751-4.
Authored by William J. Dally and John W. Poulton in 1998. Published by Cambridge University Press. ISBN 978-0-521-59292-5.