Parallel distributed seismic migration

Abstract

We report significant speed‐up for seismic migration running in parallel on networkconnected IBM RISC/6000 workstations, A sustained performance of 15 MFLOP is obtained on a single‐entry‐level model 320, and speed‐ups as high as 5 are obtained for six workstations connected by Ethernet or token ring. Our parallel software uses remote procedure calls provided by NCS (Network Computing System). We have run over a dozen workstations in parallel, but speed‐ups become limited by network data rate. Fiber‐optic communication should allow much greater speed‐ups, and we describe our preliminary results with the fiberoptic serial link adapter of the RISC/6000. We also present a simple theoretical model that agrees well with our measurements and allows speed‐up to be predicted from a knowledge of the ratio of computation to communication, which can be determined empirically before the program is parallellzed. We conclude with a brief discussion of alternative software approaches and programming models for network‐connected parallel systems. In particular, our program was recently ported to PVM and Linda, and preliminary measurements yield speed‐ups very close to those described here. Copyright © 1993 John Wiley & Sons, Ltd