Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Multitasking the three-dimensional transport code TORT on CRAY platforms

Conference ·
OSTI ID:219389
 [1]; ;  [2]
  1. Oak Ridge National Lab., TN (United States). Computational Physics and Engineering Div.
  2. Lockheed Martin Corp., Schenectady, NY (United States)

The multitasking options in the three-dimensional neutral particle transport code TORT originally implemented for Cray`s CTSS operating system are revived and extended to run on Cray Y/MP and C90 computers using the UNICOS operating system. These include two coarse-grained domain decompositions; across octants, and across directions within an octant, termed Octant Parallel (OP), and Direction Parallel (DP), respectively. Parallel performance of the DP is significantly enhanced by increasing the task grain size and reducing load imbalance via dynamic scheduling of the discrete angles among the participating tasks. Substantial Wall Clock speedup factors, approaching 4.5 using 8 tasks, have been measured in a time-sharing environment, and generally depend on the test problem specifications, number of tasks, and machine loading during execution.

Research Organization:
Oak Ridge National Lab., TN (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC05-96OR22464
OSTI ID:
219389
Report Number(s):
CONF-960415--25; ON: DE96008088
Country of Publication:
United States
Language:
English