Cray 2 and Beyond

With the success of the Cray-1 the next model had to be faster still. The Cray-2 was to be smaller and this needed new a hardware design. Using special 3D modules to hold the chips Cray managed to pack 250,000 devices into a horseshoe shaped cabinet even smaller than the Cray-1. Every connection was reduced to less than 16 inches and the result was a cycle time of 4ns i.e. a clock rate of around 120MHz. Half way through the project Cray decided to switch from bi-polar chips to cooler CMOS devices. Cooler they may have been but getting rid of the heat was still a problem. This time he decided to flood the machine with Fluorinert - which also resulted in the Cray-2's nickname "the computer in the aquarium".

Cray Research was selling more and more supercomputers. Partly because falling component costs allowed it to cut the price of the machines by $5 to $10 million. Seymour Cray was once again involved in an important successful company and he wasn't happy. It just didn't leave enough time for building supercomputers.

In 1981 he left the board of Cray Research and went to work again at Chippewa Falls. He had an agreement with the company that he could pursue any line of development even if Cray Research wasn't interested in it. It looks as if he had found paradise for the second time. But Cray Research needed to carry on making money so in 1985 the Cray X-MP was launched. Its design was mostly the result of the work of Steve Chen and not Seymour Cray who was busy at work on the Cray-3.

The Cray-3

The Cray-3 was eventually delivered in 1993 -  a small, four foot high grey box with none of the charisma of the earlier machines. It was revolutionary in that it used gallium arsenide semiconductors in its chips for speed and low power. Even though its 128M words of memory, four processors and 20Gbytes of disk storage may not seem impressive today the 90Kwatts of power it consumed is. The Cray 3 wasn't a great sucess and it probably was the cause of the eventual collapse of the company in 1995. The machine was good but times had changed - the easing in the cold war resulted in a reduced need for supercomputers and the age of the massively parallel computer was underway.

Cray set up a new company, SRC Computers, and started the design of his own massively parallel machine which focused on communications and memory performance, the bottleneck that hampered many parallel designs. Design had only just started when Cray was involved in a fatal car accident, dying of his injuries after two weeks, at the age of 71. 

Seymour Cray was perhaps the last of the lone supercomputer designers. His designs depended on size and engineering smartness. Today's supercomputers depend on single chip processors and use large interconnected arrays to create parallel machines. Designing one doesn't need the sort of skills that Cray had in plenty. It isn't work that a single man could or would want to carry out and group work was never his strong point.

In the afternoons he would disconnect his phone. He would even refuse invitations to speak at scientific gatherings. He believed that a supercomputer was best built by one man working alone and keeping the whole design inside his head. This no doubt resulted in his reputation as a recluse and an eccentric - but you can only envy his freedom. When taking his annual holiday to the Tropics he would buy a new car. Rather than be side tracked into the time wasting chore of choosing one, he simply picked the one nearest the right of the showroom door.

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