[CPMD-list] Performance on beowulf cluster

[Davide Provasi]

 I am trying to optimize the preformance of  CPMD (version 3.7.1) 
 on a beowulf cluster. The code is compiled with IFC Compiler 
 (Version 7.1, Build 20030521Z),Libraries:  ATLAS 3.4.1, 
 LAPACK 3.0+updates, optimized for Pentium 4
 My makefile contains the following flags:

>   FFLAGS =  -xiMK -pc64 -mp1 -ip -unroll -cm -w90 -w95 
>   -I/home/libs/mpich-1.2.5/include -safe_cray_ptr
>   LFLAGS =  -xiMK -Vaxlib -L/home/libs/ATLAS/Linux_P4/lib -lcblas -lf77blas 
>   -latlas -L/home/libs/LAPACK/libs -llapackP4 
>   -L/home/libs/ATLAS/Linux_P4/lib -lcblas -lf77blas -latlas 
>   -L/home/libs/mpich-1.2.5/lib -lmpich -safe_cray_ptr
>   CFLAGS =
>   CPP = /lib/cpp -P -C -traditional
>   CPPFLAGS = -D__Linux -D__PGI -DLAPACK -DFFT_DEFAULT -DLINUX_IFC -DPARALLEL 
>   -DMP_LIBRARY=__MPI
>   CC = gcc -O3 -Wall
>   FC = ifc -c -tpp7 -O3
>   #-safe_cray_ptr
>   LD = ifc -tpp7 -O3

We have noticed a large Elapsed time in the FFTCOM, 
and were wondering whether we could improve this.

 ****************************************************************
 *                                                              *
 *                            TIMING                            *
 *                                                              *
 ****************************************************************
 SUBROUTINE            CALLS         CPU TIME        ELAPSED TIME
    FFT-G/S            19040           291.46              292.76
   S_INVFFT             4736           253.78              253.85
     RHOOFR               54           103.04              102.86
    S_FWFFT             1280            69.84               69.65
        RGS               54            64.93               64.94
       VPSI              114            43.68               44.02
     EICALC               55            41.43               41.39
     FFTCOM             6512            32.04             1756.83
      FWFFT              275            25.34               25.28
     GCENER               55            22.26               22.27
      OVLAP               19            21.67               21.72
     RNLSM1              150            21.02               21.11
     INVFFT              221            18.21               18.26
    FNONLOC              114            12.58               12.59
     ROTATE               18            11.37               11.37
     PCGRAD               18            10.21               10.54
     GRADEN               55             7.76                7.94
      PHASE              496             6.77                6.94
     OVLAP2               96             5.00                5.82
     XCENER               55             4.80                4.74
     FORCES               18             3.30                3.37
 ----------------------------------------------------------------
 TOTAL TIME                           1070.49             2798.24
 ----------------------------------------------------------------

thank you in advance,

Davide

-----------------------------
Davide Provasi
University of Milano,
Physics Department
via Celoria 16, 20133 Milano
Phone +39 02 5031 7 717
-----------------------------