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SSP 1995 projects: |
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Modelling is critical for the design and interpretation of electromagnetic surveys used to explore the structure of the Earth. However, the complexity of the Earth models which may be considered remains limited by computational requirements.
This project applies the computational power of workstation clusters and massively parallel machines such as the Cray T3D to electromagnetic modelling problems. A parallel version of the EM3D modelling code has been developed to run on Unix-based platforms. Portability and reliability are assured by the use of the Message Passing Interface (MPI) and the task farming parallelisation scheme as supported by the Edinburgh Parallel Computing Centre's Parallel Utilities Libraries.
The porting to MPI of a previous version based on the CHIMP message passing system required only sixteen lines of source code to be changed. Excellent speedup is obtained on the workstation cluster. This increase in performance has allowed for more rapid modelling and interpretation of three dimensional geological structures.
Ultimate performance should be provided by closely-coupled massively parallel supercomputers. A naive port of the MPI based EM3D code required only makefile and script changes but gave poor performance. Improved performance can be obtained by optimisation for the T3D's architecture at the expense of programming effort and portability.
Bill Day
worked on this project.
Compressed PostScript of the project's final report is available here (123423 bytes) .
Bill has also made an HTML version of the report available from his Minnesota account.
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Webpage maintained by
mario@epcc.ed.ac.uk
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