HITAC S 820

The HITAC S-820 is a vector supercomputer developed, manufactured and marketed by Hitachi. Announced in July 1987, it was Hitachi's second supercomputer, succeeding the HITAC S-810. The S-820 is categorized as a second generation Japanese supercomputer.

There were five models. The first two, the mid-range S-820/60 with a peak performance of 1.5 GFLOPS and the top-end S-820/80 with a peak performance of 3.0 GFLOPS, were announced in July 1987. These two models differ in the number of vector pipelines installed. In May 1988, the S-820/20 and S-820/40 were announced, followed by the S-820/15 in November 1989.