Seymour Cray

Even as the CDC 1604 was starting to ship to customers in 1960, Cray had already moved on to designing other computers.

He first worked on the design of an upgraded version (the CDC 3000 series), but company management wanted these machines targeted toward "business and commercial" data processing for average customers.

Cray did not enjoy working on such "mundane" machines, constrained to design for low-cost construction, so CDC could sell many of them.

His desire was to "produce the largest [fastest] computer in the world".

So after some basic design work on the CDC 3000 series, he turned that over to others and went on to work on the CDC 6600.

Nonetheless, several special features of the 6600 first started to appear in the 3000 series.

Although in terms of hardware the 6600 was not on the leading edge, Cray invested considerable effort into the design of the machine in an attempt to enable it to run as fast as possible.

Unlike most high-end projects, Cray realized that there was considerably more to performance than simple processor speed, that I/O bandwidth had to be maximized as well in order to avoid "starving" the processor of data to crunch.

He later noted, "Anyone can build a fast CPU. The trick is to build a fast system."

The 6600 was the first commercial supercomputer, outperforming everything then available by a wide margin.

While expensive, for those that needed the absolutely fastest computer available there was nothing else on the market that could compete.

When other companies (namely IBM) attempted to create machines with similar performance, they stumbled (IBM 7030 Stretch).

In the 6600, Cray had solved the critical design problem of "imprecise interrupts", which was largely responsible for IBM's failure.

He did this by replacing I/O interrupts with a polled request issued by one of ten so-called peripheral processors, which were built-in mini-computers that did all transfers in and out of the 6600's central memory.

The following CDC 7600 even improved the speed advantage by a factor of five.

Seymour Roger Cray (September 28, 1925 – October 5, 1996 ) was an American electrical engineer and supercomputer architect who designed a series of computers that were the fastest in the world for decades, and founded Cray Research which built many of these machines.

Called "the father of supercomputing", Cray has been credited with creating the supercomputer industry.

Joel S. Birnbaum, then chief technology officer of Hewlett-Packard, said of him: "It seems impossible to exaggerate the effect he had on the industry; many of the things that high performance computers now do routinely were at the farthest edge of credibility when Seymour envisioned them."

Larry Smarr, then director of the National Center for Supercomputing Applications at the University of Illinois said that Cray is "the Thomas Edison of the supercomputing industry."

Cray was born in 1925 in Chippewa Falls, Wisconsin, to Seymour R. and Lillian Cray.

His father was a civil engineer who fostered Cray's interest in science and engineering.

As early as the age of ten he was able to build a device out of Erector Set components that converted punched paper tape into Morse code signals.

The basement of the family home was given over to the young Cray as a "laboratory".

Cray graduated from Chippewa Falls High School in 1943 before being drafted for World War II as a radio operator.

He saw action in Europe, and then moved to the Pacific theatre where he worked on breaking Japanese naval codes.

On his return to the United States he earned a B.Sc. in electrical engineering at the University of Minnesota, graduating in 1949, followed by a M.Sc. in applied mathematics in 1951.

In 1950, Cray joined Engineering Research Associates (ERA) in Saint Paul, Minnesota.

ERA had formed out of a former United States Navy laboratory that had built codebreaking machines, a tradition ERA carried on when such work was available.

ERA was introduced to computer technology during one such effort, but in other times had worked on a wide variety of basic engineering as well.

Cray quickly came to be regarded as an expert on digital computer technology, especially following his design work on the ERA 1103, the first commercially successful scientific computer.

He remained at ERA when it was bought by Remington Rand and then Sperry Corporation in the early 1950s.

At the newly formed Sperry Rand, ERA became the scientific computing arm of their UNIVAC division.

Cray, along with William Norris, later became dissatisfied with ERA, then spun off as Sperry Rand.

In 1957, they founded a new company, Control Data Corporation.

By 1960 he had completed the design of the CDC 1604, an improved low-cost ERA 1103 that had impressive performance for its price.

In 1963, in a Business Week article announcing the CDC 6600, Seymour Cray clearly expressed an idea that is often misattributed to Herb Grosch as so-called Grosch's law:

"Computers should obey a square law — when the price doubles, you should get at least four times as much speed."

During this period Cray had become increasingly annoyed at what he saw as interference from CDC management.

Cray always demanded an absolutely quiet work environment with a minimum of management overhead, but as the company grew he found himself constantly interrupted by middle managers who – according to Cray – did little but gawk and use him as a sales tool by introducing him to prospective customers.

Cray decided that in order to continue development he would have to move from St. Paul, far enough that it would be too long a drive for a "quick visit" and long-distance telephone charges would be just enough to deter most calls, yet close enough that real visits or board meetings could be attended without too much difficulty.