PSTSWM SP3-200 Algorithm Comparison

Performance Studies using

PSTSWM

IBM SP3-200 Algorithm Comparison

(transpose FFT experiment B2 )

Date/Person: June 6, 1999 / P. Worley
Platform: IBM SP3 at Oak Ridge National Laboratory (morgan.ccs.ornl.gov):
     62 2-way Winterhawk I SMP nodes (200 MHz POWER3 with 4MB L2 cache, equivalent to RS/6000 Model 260)
Environment: AIX 4.3.2;   PSSP 3.1
Code Version: 6.5
Compilation Options: mpxlf -O3 -qarch=auto -qtune=auto -qcache=auto
Link Options: -bmaxdata:0x70000000
Math Library: ESSL
Communication Library: MPI over the switch using user space for internode communication
MPI using IP for intranode communication
Number of Timesteps: 12
Results:

Transpose FFT (mpi) / Row Major Processor Ordering
Algorithm Comparison
  T21L16    T21L16    T42L16    T42L32    T42L16    T85L32 
  P=32x2     P=16x4     P=8x8     P=32x2     P=16x4     P=8x8  
  optimal algorithm   swtrans  swtrans  srtrans  swtrans  srtrans  swtrans 
  (alltoallv-min)/min     0.046    0.068    0.031    0.135    0.033    0.039 
  (generic-min)/min     0.495    0.361    0.088    0.191    0.125    0.014 

Patrick H. Worley / ( worleyph@ornl.gov)
Last Modified Monday, 15-Jul-2002 10:16:01 EDT.