Three-Dimensional Dip Moveout On the Sx-2: an XMU Implementation

Abstract

In the past few years, a seismic processing technique called dip moveout (DMO) has been investigated with the objective of improving the quality of seismic data. The main memory requirement of a three-dimensional DMO program with a realistic data set may be on the order of several gigabytes, a requirement that none of today's supercomputers can satisfy. One solution may be to implement out-of-core algorithms, which process only a subset of data at any time. So, only (part of) the instructions and part of the data need to reside in the main memory. The entire program data could reside on a secondary storage unit. The NEC SX-2 supercomputer used in this study has a main memory size of 128 me gabytes. It also has an extended memory unit (XMU) size of 1 gigabyte. The XMU is connected to the main memory unit by a 1.3 gigabyte/sec channel. An out-of- core algorithm has been implemented on the SX-2. The XMU was used to store the program data. The program was tested with three-dimensional data from an acoustic tank used for physical modeling. The results indicate that the speedup between the SX-2 and the VAX-11/780 is in excess of 100.

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