The CRAY-1 computer system

TLDR

The CRAY‑1 is the only computer built to satisfy ERDA’s Class VI requirement of 20–60 million floating‑point operations per second. This paper describes the CRAY‑1, its architectural evolution, and the manufacturing challenges overcome. The authors present the CRAY‑1’s vector‑processing architecture and its CFT Fortran compiler, which automatically vectorizes innermost loops without source modifications, enabling immediate scientific use. The CFT compiler protects users’ prior Fortran development effort by allowing direct use on the CRAY‑1.

Abstract

This paper describes the CRAY-1, discusses the evolution of its architecture, and gives an account of some of the problems that were overcome during its manufacture. The CRAY-1 is the only computer to have been built to date that satisfies ERDA's Class VI requirement (a computer capable of processing from 20 to 60 million floating point operations per second) [1]. The CRAY-1's Fortran compiler (CFT) is designed to give the scientific user immediate access to the benefits of the CRAY-1's vector processing architecture. An optimizing compiler, CFT, “vectorizes” innermost DO loops. Compatible with the ANSI 1966 Fortran Standard and with many commonly supported Fortran extensions, CFT does not require any source program modifications or the use of additional nonstandard Fortran statements to achieve vectorization. Thus the user's investment of hundreds of man months of effort to develop Fortran programs for other contemporary computers is protected.