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Seymour Cray

Overview

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. Known as “the father of supercomputing,” he founded Cray Research and created the iconic Cray-1, the first commercially successful vector supercomputer. His machines transformed NWP by enabling atmospheric models of unprecedented resolution and complexity.

Early Life

  • Born: September 28, 1925, in Chippewa Falls, Wisconsin
  • Father: Seymour R. Cray Sr., a civil engineer for the city of Chippewa Falls
  • Mother: Lillian Cray
  • Showed engineering talent from childhood: tinkered with radios in the family basement
  • Built a punched-tape-to-Morse-code device from Erector Set components by age 10 – a device that converted punched paper tape into electrical signals
  • Won a science talent prize as a high school senior for building an automatic telegraph machine
  • Graduated from Chippewa Falls High School in 1943

Military Service

  • Drafted for World War II after high school
  • Served as a radio operator in Europe
  • Transferred to the Pacific theater where he worked on breaking Japanese naval codes – an early encounter with computing applied to cryptanalysis
  • This experience shaped his later career: ERA, where he began, had formed out of the same Navy codebreaking operation

Education

  • B.Sc. in Electrical Engineering, University of Minnesota, 1949
  • M.Sc. in Applied Mathematics, University of Minnesota, 1951

Career at Engineering Research Associates (ERA), 1950–1957

  • Joined ERA in Saint Paul, Minnesota in 1950
  • ERA had formed out of a former U.S. Navy laboratory that built codebreaking machines during WWII
  • Quickly became regarded as an expert on digital computer technology
  • Designed the ERA 1103 – the first commercially successful scientific computer
  • ERA was acquired by Remington Rand, then merged into Sperry Rand – a series of corporate mergers that frustrated Cray

Career at Control Data Corporation (CDC), 1957–1972

  • In 1957, left Sperry Rand and co-founded Control Data Corporation with William Norris and others
  • Designed a succession of progressively faster machines:

CDC 1604 (1960)

  • An improved, lower-cost version of the ERA 1103 redesigned with germanium transistors
  • One of the first commercially successful transistorized computers
  • Designed with his preferred tools: a blank notebook and a #3 pencil

CDC 6600 (1964)

  • The world’s first commercially successful supercomputer
  • Approximately 3 million instructions per second – about three times faster than the IBM 7030 Stretch
  • World’s fastest computer from 1964 to 1969
  • Designed by a team of just 34 engineers led by Cray, Jim Thornton, and Dean Roush
  • Cray relocated the development team to his hometown of Chippewa Falls to escape corporate headquarters in Minneapolis
  • IBM’s Thomas Watson Jr. reportedly wrote an internal memo asking how a team of 34 people in rural Wisconsin could outperform IBM’s massive engineering organization

CDC 7600 (1969)

  • Five times faster than the CDC 6600
  • World’s fastest computer from 1969 to approximately 1975
  • Scalar processor design; peak performance around 36 MFLOPS
  • Widely used for NWP: NCAR received CDC 7600 serial number 12 on May 24, 1971; the machine served until 1983
  • Both LLNL and NCAR reported the machine would break down at least once a day, and often four or five times
  • The CDC 7600 was the immediate predecessor to the Cray-1 at NCAR

CDC 8600 (cancelled, 1974)

  • Attempted brute-force multi-processor design
  • Project was abandoned; Cray’s major failure at CDC
  • The experience taught him valuable lessons: the Cray-1 balanced scalar and vector performance rather than pursuing speed at all costs

Departure from CDC

  • Left CDC in 1972 after growing frustration with corporate bureaucracy
  • Norris reportedly invested $250000 in startup capital for Cray’s new venture
  • According to one account, Norris asked Cray to develop a five-year plan. The reply was a short note: “Five-year goal: Build the biggest computer in the world. One-year goal: One-fifth of the above.”

Cray Research, 1972–1989

  • Founded Cray Research Inc. in 1972 in Chippewa Falls, Wisconsin
  • R&D based in Chippewa Falls; business headquarters in Minneapolis
  • Manufacturing also in Chippewa Falls – unlike CDC, where manufacturing was separate

The Cray-1 (1976)

  • The machine that defined supercomputing (see separate research file: Cray-1.md)
  • First commercially successful vector supercomputer
  • 80 MHz clock, 160 MFLOPS peak, distinctive C-shaped cabinet
  • NCAR was the first paying customer (serial #3, July 1977, $8.86 million)
  • Over 80 units sold
  • Made Cray Research a revenue-generating company upon NCAR’s acceptance in December 1977

The Cray-2 (1985)

  • Four-processor machine with Fluorinert liquid immersion cooling (see separate: Cray-2.md)
  • 1.9 GFLOPS peak; world’s fastest 1985–1987
  • 256-megaword memory (2 GB) – more than all previously delivered Cray machines combined
  • Nicknamed “Bubbles” and “the world’s most expensive aquarium”

Corporate Evolution

  • Resigned as CEO in 1980 to focus exclusively on design
  • Became an independent contractor to Cray Research
  • In 1988, relocated to Colorado Springs, Colorado with the Cray-3 project
  • The Cray-3 project was spun off as a separate company, Cray Computer Corporation (CCC)

Cray Computer Corporation, 1989–1995

  • Founded as independent entity to pursue the Cray-3 design
  • The Cray-3 used experimental gallium arsenide (GaAs) semiconductors instead of silicon
  • Only one production unit was completed (serial number S5, nicknamed “Graywolf”)
  • Delivered to NCAR on May 24, 1993, as a test and evaluation system – a poignant connection: NCAR had been Cray’s first paying customer 16 years earlier
  • The launch customer, Lawrence Livermore National Laboratory, cancelled their order in 1991
  • CCC filed Chapter 11 bankruptcy on March 24, 1995

SRC Computers

  • Founded his final company to develop massively parallel machines
  • Emphasized memory and communications performance over raw CPU speed
  • In his words: “Anyone can build a fast CPU. The trick is to build a fast system.”

Personality and Design Philosophy

The Hermit Engineer

  • Craved an absolutely quiet work environment with a minimum of management interference
  • Deliberately located his labs in rural Chippewa Falls, far from corporate headquarters and Silicon Valley
  • Kept his desk free of clutter: visitors who passed his office when he was away saw only the workbook and a pencil, both items always lined up parallel
  • Design tools: Only used #3 Ticonderoga pencils and graph paper. When asked about his tools for designing the Cray-1, he suggested using the back of the graph paper “so the lines weren’t too bright”
  • Avoided CAD tools entirely throughout his career
  • Submitted minimal status reports. One famous example read in its entirety: “Activity is progressing satisfactorily as outlined under the June plan. There have been no significant changes or deviations from the June plan.”

The Elves and the Tunnel

  • The most famous anecdote: when asked about the secrets of his success by a visiting French scientist, Cray said: “Well, we have elves here, and they help me.” He then showed his visitor a tunnel he had dug beneath his house, explaining: “While I’m digging in the tunnel, the elves will often come to me with solutions to my problem.”
  • Source note: These stories were propagated by John A. Rollwagen, then-CEO of Cray Research, and became known as “Rollwagenisms.” A former Cray Research employee, Jim Masocco, has stated that the tunnel story is largely embellished by Rollwagen. According to Masocco, Cray may have dug 4 or 5 yards of tunnel in his basement, but no more, and he “definitely never dug a tunnel to another building.” The digging began as practical excavation work – adding a basement to his Lake Wissota house – and Cray found it both relaxing and stimulating.
  • The “Rollwagenisms” label is important: Rollwagen was a gifted storyteller who shaped Cray’s public legend. Some stories contain kernels of truth enlarged into myth.

The Sailboat

  • According to legend, during winter Cray would design a sailboat, build it, and sail it during summer. As winter approached, he would hold a party and burn the boat, so that next winter he could design a new one from scratch without being “held back by last year’s ideas” – “Revolution not Evolution.”
  • Source note: Masocco states Rollwagen took a single incident where Cray burned a sailboat at his Lake Wissota house and turned it into a recurring mythic tale. The story is a “Rollwagenism.”
  • However, the underlying philosophy – designing from a clean sheet each time, never being constrained by the previous design – was genuinely characteristic of Cray’s approach.

Lake Wissota

  • Cray had a house on Lake Wissota, a few miles downstream from Chippewa Falls
  • The lake was the setting for many of the “Rollwagenism” stories
  • Activities included sailing, water-skiing, and in later years, wind-surfing

On Parallel Computing

  • Cray was famously skeptical of massively parallel architectures:
    • “If you were plowing a field, which would you rather use? Two strong oxen or 1024 chickens?”
    • He consistently believed one very fast processor was superior to a large cluster of slower ones
    • This philosophy was central to his entire career, though history has vindicated parallel computing for many applications

On Intuition

  • “I’m supposed to be a scientific person but I use intuition more than logic in making basic decisions.”

On Originality

  • “Don’t do anything that other people are doing. Always do something a little different if you can. The concept is that if you do it a little differently there is a greater potential for reward than if you do the same thing that other people are doing.”

Relationship with NSA

  • Cray’s entire career had roots in cryptanalysis, from his WWII Navy service to ERA’s origins in Navy codebreaking
  • NSA bought two CDC 6600s and a 6400 for ELINT processing during the Vietnam War
  • Cray designed Bogart, a special-purpose computer tailored specifically for cryptanalytic tasks (statistical analysis of cipher texts, pattern recognition)
  • In 1978, with NSA’s planned acquisition of its first Cray-1, Seymour agreed to visit Fort Meade and give a talk to Agency cryptanalysts and programmers
  • NSA developed its own proprietary operating system “Folklore” for Cray machines, with a proprietary language “IMP”
  • A “Folklored” Cray-1 with a dedicated tube-room for cryptanalysts became the first “client-server” system at NSA
  • NSA acquired a Cray-2 shortly after its 1985 release, attracted by its massive 256-megaword memory
  • Cray had a “profound effect on NSA’s mission from the 1950s to the 1990s” (NSA declassified assessment)
  • NSA inducted Cray into its Hall of Honor

Personal Life

  • First marriage: Verene Voll (married 1947, divorced 1978) – childhood acquaintance from Chippewa Falls, daughter of a Methodist minister, worked as a nutritionist. Three children together.
  • Second marriage: Geri M. Harrand
  • Hobbies: Skiing, windsurfing, tennis, sailing
  • Grandson: Andrew Cray (LGBTQ rights activist)
  • Had a personal bomb shelter at his Chippewa Falls property, reflecting Cold War anxieties

Death

  • September 22, 1996 (some sources say September 18): Involved in a three-car accident on Interstate 25 near the Air Force Academy in Colorado Springs
  • His Jeep Cherokee was struck by another vehicle while merging; the Jeep rolled three times
  • Suffered a broken neck, severe head injuries, and fractured ribs
  • Hospitalized at Penrose Hospital in Colorado Springs
  • Died October 5, 1996, two weeks after the accident, at age 71
  • The other driver was cited for careless driving

Legacy and Honors

  • IEEE Seymour Cray Computer Engineering Award established in 1997 in his honor
  • NSA Hall of Honor inductee
  • His machines powered NWP from the mid-1970s through the 1990s at NCAR, ECMWF, and national weather services worldwide
  • The Cray-1 remains the most recognizable supercomputer ever built
  • Chippewa Falls, Wisconsin maintains a museum with multiple Cray machines

Career Timeline

Year Event
1925 Born in Chippewa Falls, Wisconsin
1943 Graduated high school; drafted for WWII
1943–1945 WWII service: radio operator, Japanese code-breaking
1949 B.Sc. Electrical Engineering, University of Minnesota
1950 Joined ERA in Saint Paul
1951 M.Sc. Applied Mathematics, University of Minnesota
1957 Co-founded Control Data Corporation
1960 CDC 1604 completed (first transistorized scientific computer for CDC)
1964 CDC 6600 released – world’s fastest computer
1969 CDC 7600 released – five times faster than 6600
1972 Left CDC; founded Cray Research
1976 Cray-1 first delivered (Los Alamos)
1977 NCAR receives Cray-1 serial #3 (July); Cray Research becomes revenue-generating
1980 Resigned as CEO of Cray Research to focus on design
1985 Cray-2 released – world’s fastest (1985–1987)
1988 Relocated to Colorado Springs with Cray-3 project
1989 Cray Computer Corporation spun off
1993 Cray-3 “Graywolf” delivered to NCAR (May 24) – only production unit
1995 CCC files Chapter 11 bankruptcy (March 24)
1996 Founded SRC Computers; car accident September 22; died October 5

Sources