A 3D forward modeling program for the Cyber 205 vector processor

A 3D acoustic wave equation modeling program was designed and implemented on the CDC Cyber 205 vector processor. The program was designed to handle a 256x256x128 spatial grid and approximately 3000 time steps within 40 hours of computing time. The Fourier method was selected as the computational basis of the 3D modeling program. Some basic features of vector processors are introduced such as pipelining, vector instructions ...etc. A brief overview of the Cyber 205 system and the algorithm used in solving the wave equation are also discussed. The design of the 3D forward modeling program has the following properties (1) Halfword (32-bit) storage and computation. (2) Four way concurrent 1/0 management (SLICE4). (3) Dynamic startup computation involving only those spatial points at which wave activity is present. The measured times and snapshots of the test models are presented. Factors affecting the computing time and improvements of the 3D forward modeling program are also discussed.