Cray-2

Directly from an employee in the Test and Engineering departments of Cray Research and later Cray Computer:

“After we had a fully functional VR Stack on a Cray-3 module, (‘Stack’ was Cray-3 terms and referred to the four, 1" x 1" boards interconnected vertically on a module), I took this particular Cray-2 VR module out of my desk drawer and asked Seymour to autograph it for me. This was so funny, because I handed him a brand-new Sharpie and flipped the module over so he could autograph the bottom board where there were no components, only circuit traces). And, in my mind he'd just sign it like someone being handed a football and he'd have this big giant autograph scribed on the bottom board of the module... Nope. He said, ‘Hmm. We worked hard designing this module and I don't want to cover up anyone's work. Oh... I'll just sign it up here in the corner.’”

ORIGINAL CRAY-2 COMPUTER MODULE SIGNED BY THE DESIGNER, SUPERCOMPUTER LEGEND SEYMOUR CRAY

Seymour Cray joined Engineering Research Associates (ERA) in 1951 after graduating from the University of Minnesota with a B.Sc. in Electrical Engineering and a M.Sc. in applied mathematics. He quickly became respected among the engineers and was assigned the difficult task of designing a control system for the ERA 1103, which became the first commercially successful scientific computer.

Cray became dissatisfied with ERA after they had been bought first by Remington Rand and then by the Sperry Corporation. He, along with William Norris, one of ERA's founders, left to form Control Data Corporation (CDC). There Cray designed the CDC 1604, performed initial work on the 3000 series, designed the CDC 6600, which was the first successful supercomputer, and the CDC 7600.

Cray left CDC in 1972 to form Cray Research on apparently good terms as he was given a sizeable investment from CDC. The Cray-1, Cray Research’s first release, was a supercomputer 5 times faster than the CDC 7600, and became one of the most successful supercomputers in history. It sold over 100 units at a cost of almost $8 million each.

The Cray-2 was his follow up and his first design utilizing computer-aided design (CAD) software. Cray was again able to double the clock speed of his previous machine through increased density of the smaller ICs available at the time. The computer would use four processors, and Cray also separated the memory into quadrants that could be accessed simultaneously, allowing for higher parallelism.

The other major innovation was Cray's ingenious idea to achieve the necessary density by stacking the circuit boards closely together connected by pins sticking up from the surface. A stack of 8 boards would only be a couple of inches high. This necessitated an advanced cooling method since air would not be able to flow between the layers so a new inert liquid manufactured by 3M, Fluorinert, was used. Cray would also use the same liquid immersion cooling method in his follow-up, the Cray-3.

The Cray-2 was finally released in 1985 and at 1.9 GFLOPS peak performance, was the fastest computer in the world. The Cray-1 was the first commercially successful supercomputer to utilize vector technology whereby it was able to store and manipulate large one-dimensional arrays of data rather than single data items only. The Cray-2 contained 4 of these vector processors running in parallel. The present module is from one of the Cray-2 vector processors.

REFERENCES:

Murray, Charles J. The Supermen. New York: John Wiley & Sons, [1997].