PSTSWM T3E-900 Algorithm Comparison

Performance Studies using

PSTSWM

SGI/Cray Research T3E-900 Algorithm Comparison

(transpose LT experiment I-B )

Date/Person: May 11, 1998 / P. Worley
Platform: T3E-900 at National Energy Research Scientific Computing Center (mcurie.nersc.gov):
   532 450-MHz DEC Alpha EV5 RISC processors
Environment: UNICOS/mk 2.0.2.28
mpt 1.2.0.2
Cray CF90 Version 3.0.2.1
Code Version: 6.3
Compilation Options: -dp -Oscalar3 -Wl,-Dstreams=on
Math Library: libsci
Communication Library: MPI
SHMEM
Number of Timesteps: 12
Results:

Transpose LT (1) (mpi) / Row Major Processor Ordering
Algorithm Comparison
  T21L16    T21L16    T42L16    T42L32    T42L16    T85L32 
  P=2x32     P=4x16     P=8x8     P=2x32     P=4x16     P=8x8  
  optimal algorithm   alltoallv  alltoallv  alltoallv  alltoallv  alltoallv  alltoallv 
  (alltoallv-min)/min     0.000    0.000    0.000    0.000    0.000    0.000 
  (generic-min)/min     0.297    0.045    0.039    0.059    0.082    0.005 

Transpose LT (1) (shmem) / Row Major Processor Ordering
Algorithm Comparison
  T21L16    T21L16    T42L16    T42L32    T42L16    T85L32 
  P=2x32     P=4x16     P=8x8     P=2x32     P=4x16     P=8x8  
  optimal algorithm   swtrans  srtrans  srtrans  srtrans  srtrans  srtrans 
  (generic-min)/min     0.167    0.086    0.027    0.036    0.049    0.017 

Transpose LT (1) (combined) / Row Major Processor Ordering
Communication Library Comparisons
  T21L16    T21L16    T42L16    T42L32    T42L16    T85L32 
  P=2x32     P=4x16     P=8x8     P=2x32     P=4x16     P=8x8  
  optimal library   shmem  shmem  shmem  shmem  shmem  shmem 
  (alltoallv-min)/min     0.662    0.747    0.252    0.213    0.276    0.125 
  (mpi-min)/min     0.662    0.747    0.252    0.213    0.276    0.125 

Patrick H. Worley / ( worleyph@ornl.gov)
Last Modified Monday, 15-Jul-2002 10:28:47 EDT.