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Gene Myron Amdahl

Born: November 16, 1922, Flandreau, South Dakota Died: November 10, 2015, Palo Alto, California (aged 92; pneumonia, after years of Alzheimer’s disease)

Early Life

Born to a farming family of Norwegian and Swedish immigrant descent in Flandreau, South Dakota, approximately 50 miles from Sioux Falls. Grew up in modest circumstances: attended a one-room schoolhouse that lacked electricity until rural electrification reached the area during his high school years. The family had property in Amdahl, Norway, which featured a natural “Amdahl troll” rock formation.

After the Pearl Harbor attack in 1941, Amdahl attempted to enlist in the military but was rejected – his farming skills were deemed essential to the war effort. He later joined the Navy in 1944, where he taught radar at training centers across the United States.

Education

  • B.S. in Engineering Physics, South Dakota State University (1948)
  • M.S. in Theoretical Physics, University of Wisconsin-Madison (1949)
  • Ph.D. in Theoretical Physics, University of Wisconsin-Madison (1952); advisor: Robert G. Sachs
  • Doctoral thesis: “A Logical Design of an Intermediate Speed Digital Computer,” describing the Wisconsin Integrally Synchronized Computer (WISC), now housed in the Computer History Museum
  • Honorary D.Sc., University of Wisconsin-Madison (1979)

Married Marian Delaine Quissell, also from rural South Dakota, in 1946.

IBM Career

First Stint (1952–1955)

IBM recruited Amdahl directly from graduate school. He became the chief design engineer of the IBM 704 – IBM’s first commercial computer to use floating-point arithmetic hardware and the machine for which FORTRAN was developed. Amdahl predicted the 704 would far outsell IBM’s marketing department estimate of six units. He projected thirty-two; in fact, one hundred and forty were sold.

Also worked as initial planner for the IBM 709 and the IBM 7030 Stretch project.

Left IBM in December 1955, frustrated with bureaucracy. Worked at Ramo-Wooldridge in Los Angeles on the RW440 process control computer, and later at Aeronutronic.

Second Stint (1960–1970)

Returned to IBM in September 1960. Became the chief architect of the IBM System/360, arguably the most important computer family ever designed. The System/360 was revolutionary: “a family, all running the same software,” eliminating the requirement to rewrite all software each time hardware was upgraded. This concept of a compatible computer family became the industry standard.

Named an IBM Fellow in 1965 – the company’s highest technical honor, granting freedom to choose research direction. Headed IBM’s Advanced Computing Systems (ACS) Laboratory in Menlo Park, California.

Left IBM for the final time in September 1970, after his proposals for next-generation computer development were rejected.

Amdahl’s Law (1967)

At the Spring Joint Computer Conference in Atlantic City on April 18-20, 1967, Amdahl presented a three-page paper: “Validity of the Single Processor Approach to Achieving Large Scale Computing Capabilities” (AFIPS Conference Proceedings, Vol. 30, pp. 483-485).

The paper argued against the prevailing enthusiasm for massively parallel computing. Amdahl’s Law states that the overall speedup of a program from parallelization is fundamentally limited by the fraction of the program that must execute sequentially. If a fraction f of a program is inherently serial, then the maximum speedup from N processors is 1/(f + (1-f)/N). As N approaches infinity, the speedup is bounded by 1/f.

Described by later scholars as “simple, elegant, and amazingly useful,” Amdahl’s Law remains a foundational concept in computer architecture and is taught in virtually every parallel computing course. The paper arose from a debate at the conference with Daniel Slotnick, architect of the ILLIAC IV parallel computer.

Amdahl Corporation (1970–1979)

Founded Amdahl Corporation in Sunnyvale, California, in September 1970, with major backing from Fujitsu (Japan). The company manufactured IBM-compatible (“plug-compatible”) mainframes that ran IBM software but were cheaper, faster, and more reliable.

  • First product: Amdahl 470V/6 (1975) – a replacement for IBM’s System 370/168
  • By 1979: over $1 billion in cumulative sales, 6000+ employees, 22% of the large mainframe market
  • Business Week and Fortune profiled Amdahl as a “brightest new star” challenging IBM (1973)
  • Also developed VM/PE, a software performance enhancement for IBM’s MVS operating system

Amdahl shifted to Chairman Emeritus in 1979 and retired from the company in 1980.

Later Ventures

  • Trilogy Systems Corporation (1979): Ambitious attempt to build mainframes using wafer-scale integration – entire processors on a single silicon wafer. Raised $60 million in the largest public offering for a startup at that time. The technology proved unworkable; the venture failed.
  • Elxsi (1985): Trilogy acquired this minicomputer company; Amdahl served as chairman until 1989.
  • Andor International Ltd. (1987): Another attempt at IBM-compatible mainframes; went bankrupt by 1995.
  • Commercial Data Servers, Inc. (1996): Super-cooled processor designs.
  • Xbridge Systems: Focused on mainframe data security.

Personality and Quotes

  • Valued autonomy and control over his own work above all else: “I’m not going to be in control of what I want to do any time in the future” – his reason for leaving IBM the first time.
  • Resisted becoming “a peg-in-a-hole” within large bureaucratic structures.
  • Serial entrepreneur despite repeated failures after Amdahl Corporation; kept founding companies into his 70s.
  • The recurring pattern of his career: brilliant technical vision, impatience with corporate constraints, departure, and independent pursuit.

Awards and Honors

  • National Academy of Engineering (1967)
  • IBM Fellow (1965)
  • IEEE Fellow (1970)
  • IEEE Computer Society W. Wallace McDowell Award (1976)
  • Distinguished Fellow, British Computer Society (1979)
  • Harry H. Goode Memorial Award, IEEE (1983)
  • ACM-IEEE Computer Society Eckert-Mauchly Award (1987)
  • IEEE Computer Entrepreneur Award (1989)
  • London Times “1,000 Makers of the 20th Century” (1991)
  • Computer History Museum Fellow (1998)
  • SIGDA Pioneering Achievement Award (2007)
  • Gene M. Amdahl Professorship of Computer Sciences established at University of Wisconsin-Madison (2013)

Family

Married Marian Delaine Quissell (1946). Three children: Andrea Leigh, Beth Delaine, and Carlton Gene Amdahl. Survived by wife, children, five grandchildren, and one great-grandchild.

Connections to Others

  • John Backus: FORTRAN was developed specifically for Amdahl’s IBM 704
  • Daniel Slotnick: Debated parallel vs. serial computing at the 1967 conference, prompting Amdahl’s Law
  • Robert G. Sachs: Doctoral advisor at Wisconsin
  • Fujitsu: Major financial backer of Amdahl Corporation

Sources