Control Data Corporation

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Control Data Corporation, or CDC, was one of the pioneering supercomputer firms. For most of the 1960s they built the fastest computers in the world, by far, only losing that crown in the 1970s to what was effectively a spinoff. They were well known and highly regarded throughout the industry at one time, but today are largely forgotten.

During World War II the US Navy had contracted for the design of a number of code-breaking machinery designs. Engineering Research Associates (ERA) was a small company formed by a number of the people working on these efforts, and in the post-war era they continued work with the Navy on general computing machines for the same role. In the early 1950s a minor political debate brokeout in Congress about the Navy essentially "owning" ERA, and the company was eventually forced to sell out to Remington Rand in 1952.

ERA had just completed the design of their transistorized ERA 1103 computer, and although Rand kept the ERA team together and developing new products, they were most interested in ERA's drum memory systems. Rand soon merged with Sperry Corporation to become Sperry Rand, and in the process of merging the companies, the ERA division was folded into Sperry's Univac division. As the Sperry "big company" mentality encroached on the decision-making of the ERA founders, they eventually got fed up and decamped to form Control Data in 1957. Of the members forming CDC, William Norris was the unanimous choice to become CEO of the new company. Seymore Cray was likewise chosen to be the chief designer, but was still in the process of completing the 1103-based Navy Tactical Data System and did not leave to join CDC until this was complete.

CDC started business by selling parts, mostly drum systems, to other companies. After Cray joined they also released a slightly-updated version of one of their 48-bit 1103 design as the CDC 1604 in 1959, with the first machine delivered to the US Navy in 1960. A 12-bit cut down version was also released as the CDC 160 in 1960, arguably the first minicomputer. New versions of the basic 1604 architecture were re-built into the CDC 3000 series, which sold through the early and mid-1960s.

In 1962 Norris agreed to set Cray up in his own lab in his hometown of Chippewa Falls, WI. Cray argued that Norris moved from Rand after becoming fed up with the bureaucracy and set up in his own hometown, so Cray, becoming fed up with HQ, should be given the same option. In the new lab Cray, Jim Thornton and Dean Roush put together a team of 34 engineers, and started design of a radically faster machine. In 1964 this was released as the CDC 6600, outperforming everything on the market by roughly ten times. The 6600 had a simple CPU, but used a series of external I/O processors to offload many common tasks. That way the CPU could devote all of its time and circuitry to processing data while the other controllers dealt with mundane tasks like punching cards and running disks. Using late-model compilers the machine still racks up .5 MFlops, while hand-coded assembly can deliver about 1 MFlop, impressive considering that it is about 40 years old. Smaller versions were released as the CDC 6000, 6400 and 6500 series.

It was at this point that IBM took notice of the new company. At the time Thomas J. Watson asked (paraphrased) how is it that this tiny company of 20 people can be beating us when we have thousands of people?, to which Cray replied you just answered your own question. In 1965 IBM started an effort to build their own machine that would be even faster than the 6600, the ACS. Two hundred people were sent to the west coast to run the project away from corporate prodding, at which point nothing happened. ACS was eventually cancelled in 1969 after producing nothing, and 190 of the 200 employees stayed on the coast rather than suffer being recalled to IBM in New York.

In the short term IBM also went ahead and announced a new version of the famed System/360 that would be just as fast as the 6600. This machine didn't exist, but that didn't stop sales of the 6600 drying up while people waited for its release – a tactic known today as FUD and more commonly associated with Microsoft. Norris didn't take this lying down, and a year later filed an anti-trust suit against IBM, eventually winning over 600 million dollars and picking up several parts of IBM's empire in the process.

The same month they won against IBM they also announced their new machine, the CDC 7600. Cray had started the design even before the 6600 was shipping, and allowed it to mature fully. This machine ran at about four to five times the speed of the 6600, yet it was almost perfectly backward compatible. Much of this speed increase was due to extensive use of pipelining, a technique that allows different parts of the CPU to work on different parts of the instruction processs at the same time. The time to run any particular instruction is no faster, but the program as a whole moves through the system more quickly as the instructions are cued up.

Cray then turned to the latest in the series, the CDC 8600. The 8600 was essentially four 7600's in a single, much smaller, case. The smaller size and shorter signal paths allowed the 8600 to run at much higher clock speeds, which was combined with higher speed memory for most of the performance gains. Unfortunately the 8600 was "old school" in terms of physical construction, using individual components soldered to cards. There were so many solder joints on the 8600 that the machines never worked reliably, one bad joint and the machine was "flaky". Cray decided that a re-design was needed.

CDC also had another project called STAR underway, led by Cray's former collaborator on the 6600, Jim Thornton. Unlike the 8600's "put four 7600s in a box" solution to the speed problem, the STAR was a new design using a technique we know today as a vector processor. By highly pipelining math instructions with purpose-built instructions and hardware, overall math processing could be dramatically improved in a machine that was otherwise slower than a 7600, although the particular set of problems it would be best at was limited in comparison to the "generalist" 7600.

The two projects competed for limited funds in the late 1960s, and in 1972 Cray had become fed up enough to leave and form Cray Research. Norris remained a staunch supporter of Cray, and even invested money into his new company. Eventually the 8600 was cancelled in 1974, and the STAR would be released in 1974. The STAR proved to have considerably worse "real world" performance than expected, eventually leading to the dismissal of Jim Thornton.

A variety of systems based on the basic 6600/7600 architecture were re-packaged at different price/performance points as the CDC Cyber, and became CDC's main product line in the 1970s. This included an updated version of the STAR architecture as well, the Cyber 205, which had considerably better performance than the first version. But by this time Cray's own designs like the Cray-1 were using the same design techniques as the STAR, yet doing it much faster due to various design details. Sales of the STAR and its follow-ons dropped, and CDC found itself being pushed out the supercomputer market by the late 1970s.

CDC decided to fight back, but Norris agreed with Cray in thinking that the company had become too ossified to be able to quickly design anything competitive. Instead he set up a new spinoff company in 1983, ETA Systems, their design goal being a machine able to process at 10 GFLOPs, about 40 times the speed of the Cray-1. The ETA design never fully matured and was unable to hit its design goals, but was nevertheless one of the fastest computers on the market and a handful were sold over the next few years. Eventually the effort ended after minor attempts at selling ETA, and in 1989 most of the employees were laid off and the remains of the company were re-folded into CDC.

Meanwhile several very large Japanese manufacturing firms were entering the market as well. The supercomputer market was too small to be able to afford more than a handful of players, and CDC started looking for other markets. One of these was the high-performance hard disk market, which was becoming more interesting as personal computers increasingly started to include them in the mid-1980s. By the early 1990s CDC was a major player in the hard drive market, their Wren series drives were particularily popular for "high end" users. They also co-developed the now-universal ATA interface with Compaq and Western Digital to lower the cost of adding low-performance drives.

Oddly, then, CDC decided to exit the hardware business entirely in 1992, and sold off their line to Seagate, who had been seriously lagging in the high-end drive market. The remains of CDC became known as Control Data Systems, Inc., with the non-computer business becoming Ceridian.

External links

• History of Large Computers (http://www.nersc.gov/~deboni/Computer.history/comp.history.chart.jpg) – Note the red bars on the graph, showing the CDC machines continually outperforming everything else; the 6600 is some ten times as fast as the fastest IBM.
• The Control Data Corporation Collection at the Charles Babbage Institute (http://www.cbi.umn.edu/collections/inv/cdc/cdcmain.htm) – The Control Data Corporation Collection was donated to the Charles Babbage Institute by the Ceridian Corporation in 1991. All of the records in this finding aid are available for research at the Charles Babbage Institute at the University of Minnesota.