CDC 8600

The CDC 8600 was the last of Seymour Cray's supercomputer designs while working for the Control Data Corporation. The "natural successor" to the CDC 6600 and CDC 7600, the 8600 was intended to be about 10 times as fast as the 7600, already the fastest computer on the market.

Development started in 1968, shortly after the release of the 7600, but the project soon started to bog down. By 1971 CDC was having cash flow problems and the design was still not coming together, prompting Cray to leave the company in 1972. The 8600 design effort was eventually cancelled in 1974, and Control Data moved on to the CDC STAR-100 series instead.

Design

In the 1960s computer design was based on mounting electronic components (transistors, resistors, etc.) on circuit boards. Several boards would be use to make a discrete logic element of the machine, known as a "module". As computer power increased the complexity of the modules did too, and even a single faulty part or solder joint would render the entire module inoperative. Cray was well known in the industry for making seemingly impossibly complex modules work.

Overall machine "cycle speed" is strongly related to the signal path – the length of the wiring – forcing high speed computers to make their modules as small as possible. This was at odds with the need to make the modules themselves more complex to increase computing power. By the late 1960s individual components had stopped getting...
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