Legends of Technology - Amdahl, Gene Myron | HackTHatCORE

Amdahl, Gene Myron

(1922 - )

American, Inventor, Entrepreneur

Gene Amdahl played a major role in designing and develop- ing the mainframe computer that dominated data process- ing through the 1970s (see mainframe ). Amdahl was born on November 16, 1922, in Flandreau, South Dakota. After having his education interrupted by World War II, Amdahl received a B.S. from South Dakota State University in 1948 and a Ph.D. in physics at the University of Wisconsin in 1952. As a graduate student Amdahl had realized that fur- ther progress in physics and other sciences required better, faster tools for computing. At the time there were only a few computers, and the best approach to getting access to sig- nificant computing power seemed to be to design one’s own machine. Amdahl designed a computer called the WISC (Wisconsin Integrally Synchronized Computer). This com- puter used a sophisticated procedure to break calculations into parts that could be carried out on separate processors, making it one of the earliest examples of the parallel com- puting techniques found in today’s computer architectures.

Designer for IBM

n 1952 Amdahl went to work for IBM, which had commit- ted itself to dominating the new data processing industry. Amdahl worked with the team that eventually designed the IBM 704. The 704 improved upon the 701, the company’s first successful mainframe, by adding many new internal programming instructions, including the ability to per- form floating point calculations (involving numbers that have decimal points). The machine also included a fast, high-capacity magnetic core memory that let the machine retrieve data more quickly during calculations. In Novem- ber 1953 Amdahl became the chief project engineer for the 704 and then helped design the IBM 709, which was designed especially for scientific applications. When IBM proposed extending the technology by build- ing a powerful new scientific computer called STRETCH, Amdahl eagerly applied to head the new project. However, he ended up on the losing side of a corporate power strug- gle, and did not receive the post. He left IBM at the end of 1955. In 1960 Amdahl rejoined IBM, where he was soon involved in several design projects. The one with the most lasting importance was the IBM System/360, which would become the most ubiquitous and successful mainframe com- puter of all time. In this project Amdahl further refined his ideas about making a computer’s central processing unit more efficient. He designed logic circuits that enabled the processor to analyze the instructions waiting to be executed (the “pipeline”) and determine which instructions could be executed immediately and which would have to wait for the results of other instructions. He also used a cache, or special memory area, in which the instructions that would be needed next could be stored ahead of time so they could be retrieved immediately when needed. Today’s desktop PCs use these same ideas to get the most out of their chips’ capabilities. Amdahl also made important contributions to the further development of parallel processing. Amdahl cre- ated a formula called Amdahl’s law that basically says that the advantage gained from using more processors gradu- ally declines as more processor are added. The amount of improvement is also proportional to how much of the cal- culation can be broken down into parts that can be run in parallel. As a result, some kinds of programs can run much faster with several processors being used simultaneously, while other programs may show little improvement. In the mid-1960s Amdahl helped establish IBM’s Advanced Computing Systems Laboratory in Menlo Park, California, which he directed. However, he became increas- ingly frustrated with what he thought was IBM’s too rigid approach to designing and marketing computers. He decided to leave IBM again and, this time, challenge it in the marketplace.

Creator of "Clones"

Amdahl resolved to make computers that were more power- ful than IBM’s machines, but that would be “plug compati- ble” with them, allowing them to use existing hardware and software. To gain an edge over the computer giant, Amdahl was able to take advantage of the early developments in integrated electronics to put more circuits on a chip with- out making the chips too small, and thus too crowded for placing the transistors. Thanks to the use of larger scale circuit integration, Amdahl could sell machines with superior technology to that of the IBM 360 or even the new IBM 370, and at a lower price. IBM responded belatedly to the competition, making more compact and faster processors, but Amdahl met each new IBM product with a faster, cheaper alterna- tive. However, IBM also countered by using a sales tech- nique that opponents called FUD (fear, uncertainty, and doubt). IBM salespersons promised customers that IBM would soon be coming out with much more powerful and economical alternatives to Amdahl’s machines. As a result, many would-be customers were persuaded to postpone pur- chasing decisions and stay with IBM. Amdahl Corporation began to falter, and Gene Amdahl gradually sold his stock and left the company in 1980. Amdahl then tried to repeat his success by starting a new company called Trilogy. The company promised to build much faster and cheaper computers than those offered by IBM or Amdahl. He believed he could accomplish this by using the new, very-large-scale integrated silicon wafer technology in which circuits were deposited in layers on a single chip rather than being distributed on separate chips on a printed circuit board. But the problem of dealing with the electrical characteristics of such dense circuitry, as well as some design errors, somewhat crippled the new computer design. Amdahl was forced to repeatedly delay the introduction of the new machine, and Trilogy failed in the marketplace. Amdahl’s achievements could not be overshadowed by the failures of his later career. He has received many indus- try awards, including Data Processing Man of the Year by the Data Processing Management Association (1976), the Harry Goode Memorial Award from the American Federa- tion of Information Processing Societies, and the SIGDA Pio- neering Achievement Award (2007).

References:

• “Gene Amdahl.” Available online. URL: http://www.thocp.net/ biographies/amdahl_gene.htm. Accessed April 10, 2007.
• Slater, Robert. Portraits in Silicon. Cambridge, Mass.: MIT Press, 1987.