Control Data Corporation - CDC 6600: Defining Supercomputing

CDC 6600: Defining Supercomputing

Meanwhile at the new Chippewa Falls lab, Seymour Cray, Jim Thornton, and Dean Roush put together a team of 34 engineers, which continued work on the new computer design. One of the ways they hoped to improve the CDC 1604 was to use better transistors, and Cray used the new silicon transistors using the planar process, developed by Fairchild Semiconductor. These were much faster than the germanium transistors in the 1604, without the drawbacks of the older mesa silicon transistors. The speed of light restriction forced a more compact design with refrigeration designed by Dean Roush. In 1964, the resulting computer was released onto the market as the CDC 6600, out-performing everything on the market by roughly ten times. When it sold over 100 units at $8 million each it was donned a supercomputer. The 6600 had a 100 ns, transistor-based CPU (Central Processing Unit) with multiple, asynchronous functional units, and it used 10 logical, external I/O processors to off-load many common tasks and core memory. That way the CPU could devote all of its time and circuitry to processing actual data, while the other controllers dealt with the mundane tasks like punching cards and running disk drives. Using late-model compilers, the machine attained a standard mathematical operations rate of 500 kilo-FLOPS, but handcrafted computer assembler delivered about 1.0 mega-FLOPS. A simpler, much slower, and much less expensive version, implemented using a more traditional serial processor design rather than the 6600's parallel functional units, was released as the CDC 6400, and a two-processor version of the 6400 was called the CDC 6500.

A Fortran compiler known as MNF (Minnesota Fortran) was developed by Lawrence A. Liddiard and E. James Mundstock at the University of Minnesota for the 6600.

It was after the delivery of the 6600 that IBM took notice of this new company. At the time, Thomas J. Watson, Jr. asked (words to the effect of) How is it that this tiny company of 34 people — including the janitor — can be beating us when we have thousands of people?, to which Cray reportedly quipped You just answered your own question. In 1965, IBM started an effort to build its own machine that would be even faster than the 6600, the ACS-1. Two hundred people were gathered together on the U.S. West Coast to work on the project, away from corporate prodding, in an attempt to mirror Cray's off-site lab. The project produced interesting computer architecture and technology, but it was not compatible with IBM's hugely successful System/360 line of computers. The engineers were directed to make it 360-compatible, but that compromised its performance. The ACS was canceled in 1969, without ever being produced for customers. Many of the engineers left the company, leading to a brain-drain in IBM's high-performance departments.

In the meantime, IBM announced a new version of the famed System/360, the Model 92, which would be just as fast as CDC's 6600. This machine did not exist, but its nonexistence did not stop sales of the 6600 from drying up, while people waited for the release of the mythical Model 92. Norris did not take this tactic, dubbed as fear, uncertainty and doubt (FUD), lying down, and in an extensive antitrust lawsuit launched against IBM a year later, he eventually won a settlement valued at $80 million. As part of the settlement, he picked up IBM's subsidiary Service Bureau Corporation (SBC), which ran computer processing for other corporations on its own computers. SBC fit nicely into CDC's existing service bureau offerings.

During the designing of the 6600, CDC had set up Project SPIN to supply the system with a high speed hard disk memory system. At the time, it was unclear if disks would replace magnetic memory drums, nor was it clear at the time whether fixed or removable disks would become the more prevalent. Thus, SPIN explored all of these approaches, and eventually it delivered a very large 28" diameter fixed disk and also a smaller multi-platter 14" removable disk-pack system. Over time, the hard disk business pioneered in SPIN would turn into a major product line.