R. A. Fatoohi
ABSTRACT
This paper presents the results of macrotasking and microtasking a Navier-Stokes algorithm on the Cray-2. The algorithm is a compact difference scheme for the solution of the incompressible, two-dimensional, time dependent Navier-Stokes equations. Two implementations of multitasking on the Cray-2 are considered. These are: macrotasking (parallelism at the subroutine level) and microtasking (parallelism at the do-loop level). These two techniques are briefly described. The implementation of the algorithm is discussed in relation to these techniques and the results for three problem sizes are presented. The timing results for both techniques are in general comparable with differences ranging between 2% to 14% depending on the problem size. The best achieved speedup in a dedicated environment is 3.62 for macrotasking and 3.32 for microtasking. Finally, comparisons are made and conclusions are drawn.
- 1.Axelrod, T. S., "Effects of Synchronization Barriers on Multiprocessor Performance," J. Parallel Computing, 3, 1986, 129-140. Google Scholar
Digital Library
- 2.Cray Research, Inc., "Cray-2 Multitasking Programmer's Manual," Publication SN-2026 B, June 1988.Google Scholar
- 3.Fatoohi, R. A. and Grosch, C. E., "Implementation of a Four Color Cell Relaxation Scheme on the MPP, Flex/32 and Cray/2," Proc. 1987 Int. Conf. Parallel Processing, pp. 424-426.Google Scholar
- 4.Fatoohi, R. A. and Grosch, C. E., "Implementation of an ADI Method on Parallel Computers," J. Scientific Computing, Vol. 2, No. 2, 1987, pp. 175-193. Google ScholarDigital Library
- 5.Fatoohi, R. A. and Grosch, C. E., "Implementation and Analysis of a Navier-Stokes Algorithm on Parallel Computers," Proc. 1988 Int. Conf. Parallel Processing, Vol. III, pp. 235-242.Google Scholar
- 6.Gatski, T. B., Grosch, C. E., and Rose, M. E., "A Numerical Study of the Two-Dimensional Navier-Stokes Equations in Vorticity-Velocity Variables," J. Comput. Phys., Vol. 48, No. 1, 1982, pp. 1-22.Google ScholarCross Ref
Index Terms
- Macrotasking and microtasking a Navier-Stokes algorithm on the Cray-2
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