Cray-2 Supercomputer: "World's Most Powerful Computer" 1986 NASA Ames Research Center

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• published: 03 Nov 2012
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more at http://computers.quickfound.net/ "The use of the Cray 2 supercomputer, the fastest computer in the world, at ARC is detailed. The Cray 2 can perform 250 million calculations per second and has 10 times the memory of any other computer. Ames researchers are shown creating computer simulations of aircraft airflow, waterflow around a submarine, and fuel flow inside of the Space Shuttle's engines. The video also details the Cray 2's use in calculating airflow around the Shuttle and its external rockets during liftoff for the first time and in the development of the National Aero Space Plane." Public domain film from NASA, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied. The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization. http://en.wikipedia.org/wiki/Cray-2 The Cray-2 was a four-processor ECL vector supercomputer made by Cray Research starting in 1985. It was the fastest machine in the world when it was released, replacing the Cray Research X-MP designed by Steve Chen in that spot. The Cray-2 was capable of 1.9 GFLOPS peak performance and was only bumped off of the top spot 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, MN, 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... 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. One solution to this problem, one that most computer vendors had already moved to, was to use integrated circuits (ICs) instead of individual components. Each IC included a selection of components from a module pre-wired into a circuit by the automated construction process. If an IC did not work, another one would be tried. At the time the 8600 was being designed the simple MOSFET-based technology did not offer the speed Cray needed. Relentless improvements changed things by the mid-1970s, however, and the Cray-1 had been able to use newer ICs and still run at a respectable 12.5 ns (80 MHz). In fact, the Cray-1 was actually somewhat faster than the 8600 because it packed considerably more logic into the system due to the IC's small size. Although IC design continued to improve, the physical size of the ICs was constrained largely by mechanical limits; the resulting component had to be large enough to solder into a system.... Cray-2 models soon settled on a design using large circuit boards packed with ICs. This made them extremely difficult to solder together, and the density was still not enough to reach their performance goals... Six months later Cray had his "eureka" moment. He called the main engineers together for a meeting and presented a new solution to the problem. Instead of making one larger circuit board, each "card" would instead consist of a 3-D stack of eight, connected together in the middle of the boards using pins sticking up from the surface (known as "pogos" or "z-pins"). The cards were packed right on top of each other, so the resulting stack was only about 3 inches high... there was too little room for air to flow between the ICs. Instead the system would be immersed in a tank of a new inert liquid from 3M, Fluorinert... Due to the use of liquid cooling, the Cray-2 was given the nickname "Bubbles", and common jokes around the computer made reference to this unique system. Gags included "No Fishing" signs, cardboard depictions of the Loch Ness Monster rising out of the heat exchanger tank, plastic fish inside the exchanger, etc. The power of the Cray-2 was 150 - 200 kW. Each vertical stack of logic modules sat above a stack of power modules which powered 5 volt bus bars, each of which delivered about 2200 amps. The Cray-2 was powered by two motor-generators, which took in 480 V three-phase.