Cray-2

Cray-2

Cray-2 central unit (foreground) and Fluorinert-cooling "waterfall" (background), on display at the EPFL.
Manufacturer	Cray Research
Type	Supercomputer
Release date	1985 (1985)
Discontinued	1990
Predecessor	Cray X-MP

The Cray-2 is a supercomputer with four vector processors built with emitter-coupled logic and made by Cray Research starting in 1985. At 1.9 GFLOPS peak performance, it was the fastest machine in the world when it was released, replacing the Cray X-MP in that spot. The Cray-2 was replaced as the world's fastest computer by the ETA-10G in 1990.

With the successful launch of his famed Cray-1, Seymour Cray turned to the design of its successor. By 1979 he had become fed up with management interruptions in what was now a large company, and as he had done in the past, decided to resign his management post and move to form a new lab. As with his original move to Chippewa Falls, Wisconsin from Control Data HQ in Minneapolis, Minnesota, Cray management understood his needs and supported his move to a new lab in Boulder, Colorado. Working as an independent consultant at these new Cray Labs, he put together a team and started on a completely new design. This Lab would later close, and a decade later a new facility in Colorado Springs would open.

Cray had previously attacked the problem of increased speed with three simultaneous advances: more functional units to give the system higher parallelism, tighter packaging to decrease signal delays, and faster components to allow for a higher clock speed. The classic example of this design is the CDC 8600, which packed four CDC 7600-like machines based on ECL logic into a 1 x 1 meter cylinder and ran them at an 8 ns cycle speed (125 MHz). Unfortunately the density needed to achieve this cycle time led to the machine's downfall. The circuit boards inside were densely packed, and since even a single malfunctioning transistor would cause an entire module to fail, packing more of them onto the cards greatly increased the chance of failure.