Gene Amdahl

Gene Myron Amdahl (born November 16, 1922) is a Norwegian American computer architect and hi-tech entrepreneur, chiefly known for his work on mainframe computers at International Business Machines (IBM) and later his own companies, especially Amdahl Corporation. He is perhaps best known for formulating Amdahl's law, which states a fundamental limitation of parallel computing.

Childhood and education

Amdahl was born to immigrant parents of Norwegian and Swedish descent in Flandreau, South Dakota. After serving in the Navy during WWII he completed a degree in engineering physics at South Dakota State University in 1948. He went on to study theoretical physics at the University of Wisconsin-Madison and completed his doctorate there in 1952, creating his first computer, the WISC. He then went straight from Wisconsin to a well paid position at IBM in June 1952.

The IBM & Amdahl years

At IBM, Amdahl worked on the IBM 704, the IBM 709, and then the Stretch project, the basis for the IBM 7030. He left IBM in December 1955 but returned in September 1960 (after working at Ramo Wooldridge and at Aeronutronic). On his return he worked on the System/360 family architecture and became an IBM Fellow in 1965, and head of the ACS Laboratory in Menlo Park, California. He left IBM again in September 1970, after his ideas for computer development were rejected, and set up Amdahl Corporation in Sunnyvale, Calif. with aid from Fujitsu.

Competing with IBM in the mainframe market, the company manufactured "plug-compatible" mainframes, shipping its first machine in 1975 - the Amdahl 470 V6, a less expensive, more reliable and faster replacement for the System 370/165. By purchasing an Amdahl 470 and plug-compatible peripheral devices from third-party manufacturers, customers could now run S/360 and S/370 applications without buying actual IBM hardware. Amdahl's software team developed VM/PE, software designed to optimize the performance of IBM's MVS operating system when running under IBM's VM operating system. By 1979 Amdahl Corporation had sold over a US $1 billion of V6 and V7 mainframes and had over 6,000 employees worldwide. The corporation went on to distribute an IBM-plug-compatible front-end processor (the 4705) as well as high-performance disk drives, both jointly developed with Fujitsu engineers.

At the Spring Joint Computer Conference, Amdahl along with three other computer architects, most notably Dan Slotnick, ILLIAC IV architect, engaged in a discussion on future architectural trends. Amdahl argued, verbally and three-written pages, for performance limitations in any special feature or mode introduced to new machines. This resulted in two, major and lesser, "laws" of computer performance regarding sequential vs. parallel processing. These arguments continue to this day.

1979–now: Entrepreneur

Amdahl left his namesake company in August 1979 to set up Trilogy Systems. With over US$200 million in funds Trilogy was aimed at designing an integrated chip for even cheaper mainframes. The chip development failed within months of the company's $60 million public offering; thereafter, the company focused on developing its VLSI technology and, when that project failed, in 1985 Trilogy merged into Elxsi. Elxsi also did poorly and Amdahl left in 1989, having already founded his next venture, Andor International, in 1987. Andor hoped to compete in the mid-sized mainframe market, using improved production techniques to make smaller, more efficient machines. Production problems and strong competition led the company into bankruptcy by 1995.

Ever determined, Amdahl co-founded Commercial Data Servers in 1996, again in Sunnyvale, and again developing mainframe-like machines but this time with new super-cooled processor designs and aimed at physically smaller systems. One such machine, from 1997, was the ESP/490 (Enterprise Server Platform/490), an enhancement of IBM's P/390 of the System/390 family. Since then, CDS has changed its name and narrowed its focus. As Xbridge Systems, the company now builds connectivity software to link mainframes and open systems. (As of early 2005, however, Xbridge's website did not list Amdahl as a member of their current management team.)

In November 2004, Amdahl was appointed to the Board of Advisors of Massively Parallel Technologies. The absence of an otherwise noticeable web presence after the turn of the millennium suggested that he had scaled back his industry involvement to an advisory capacity.


Dr. Amdahl was named an IBM Fellow in 1965, became a member of the National Academy of Engineering in 1967 and was recognized as the Centennial Alumnus of South Dakota State University in 1986. He has numerous awards and patents to his credit and has received Honorary Doctorates from his two alma maters and two other institutions as well. In 1983, Amdahl was awarded the Harry H. Goode Memorial Award by the IEEE Computer Society "in recognition of his outstanding contributions to the design, applications and manufacture of large-scale high-performance computers".[1]

In November 2007, Amdahl was recognized with the SIGDA Pioneering Achievement Award[2]. A banquet dinner in his honor featured a short talk by Amdahl on his career, and a panel debate on the future of parallel processing. Panelists included Dr. John Gustafson (well known for Gustafson's Law). The talk and debate were both videotaped, and are available through the SIGDA web page, and the ACM Digital Library[3]

See also

* Amdahl's law

* Amdahl Corporation

* IBM mainframe


1. ^ Past recipients for Harry H. Goode Memorial Award. Retrieved on 2008-01-16.

2. ^ SIGDA Pioneering Achievement Award.

3. ^ SIGDA Member Meeting at ICCAD 2007.


* Gene Amdahl - Computer History Museum Fellow Awards Recipient

* Massively Parallel Technologies Hosts Discussion With [...] Dr. Gene Amdahl and Dr. Robert Duncan [...] – Primeur Monthly, February 2005

* Oral history interview with Gene M. Amdahl. Charles Babbage Institute, University of Minnesota, Minneapolis. Amdahl starts by describing his early life and education, recalling his experiences teaching in the Advanced Specialized Training Program during and after World War II. Amdahl discusses his graduate work at the University of Wisconsin and his direction of the design and construction of WISC. Amdahl also discusses his role in the design of several computers for IBM including the STRETCH, 701, 701A, and 704. He also mentions his work with Ramo-Wooldridge, Aeronutronic, and Computer Sciences Corporation.

* Xbridge Systems

* Massively Parallel Technologies

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