ILLIAC IV was a pioneer in “massively parallel” computing. It had 64 processing elements working together, and it was designed to have up to 256. All the processing elements executed the same instruction simultaneously, and each one had its own local memory. The computer was the fourth in a line of computers built at the University of Illinois starting in 1948. It was moved to the NASA Ames Research Center in 1974, where its applications included fluid dynamics, digital image processing, and weather forecasting.

However, ILLIAC IV was too expensive and had many technical problems. Only one was ever built, and it was finally retired in 1982. Nevertheless, it stimulated the design of other parallel computers including the CDC Star, Cray 1, and TI ASC. Many of the first parallel programming languages ran on it, and it achieved record speeds for various numerical calculations at a peak of 200 million instructions per second and a one gigabit per second I/O transfer rate.

Manufacturer: Burroughs Memory technology: semiconductor
First introduced: 1974 Memory size: 2048 64-bit words per processor
CPU technology: ECL (Emitter-Coupled Logic) Clock speed: 13 MHz

D.L. Slotnick. “The Fastest Computer.” Scientific American , February 1971
C. Gordon Bell, et al. Computer Structures: Principles and Examples. New York: McGraw-Hill, 1982. p. 267
Illiac IV” in The Free Online Dictionary of Computing

ILLIAC IV computer system layout composite, bldg N-233; Photographer: Lee Jones; Date: July 13, 1972