PSTSWM AlphaSC-500 Algorithm Comparison

Performance Studies using

PSTSWM

Compaq AlphaServer SC Algorithm Comparison

(distributed LT experiment I-A1 )

Date/Person: November 4, 1999 / P. Worley
Platform: Compaq AlphaServer SC at Compaq (fsehpc):
     16 ES40 4-way SMP nodes (500 MHz Alpha 21264 with 4MB L2 cache)
Environment: Digital UNIX V5.0;   RMS 2.3.2
Code Version: 6.6.3
Compilation Options: f90 -O4 -assume accuracy_sensitive -math_library accurate -aling dcommons -align records -arch host -tune host
Math Library: none
Communication Library: MPI
Number of Timesteps: 12
Results:

Distributed LT (1) (mpi)
Algorithm Comparison
  T21L2     T42L2     T85L1     T85L4  
  P=16     P=8     P=16     P=8  
  optimal algorithm   halfsum  ringpipe  ringpipe  ringpipe 
  (allreduce-min)/min     0.187    0.257    0.378    0.502 
  (generic-min)/min     1.325    0.197    0.190    0.261 

Distributed LT (1) (combined)
Communication Library Comparisons
  T21L2     T42L2     T85L1     T85L4  
  P=16     P=8     P=16     P=8  
  optimal library   mpi  mpi  mpi  mpi 
  (allreduce-min)/min     0.187    0.257    0.378    0.502 
  (mpi-min)/min     0.000    0.000    0.000    0.000 

Patrick H. Worley / ( worleyph@ornl.gov)
Last Modified Monday, 15-Jul-2002 10:03:18 EDT.