[gmx-developers] Fortran/Power6 kernels

[Sebastian Fritsch]

Hi everybody,


I tried to use the fortran kernels (single prec.) in the developer 
version, but found they give strange results. The rdf of my (spce-water, 
reaction field) test system looks completely messed up . Also the force 
calculation takes now only about 5% (for standard kernels 68%) of the 
computer time, which makes me think that in the fortran kernels actually 
nothing is calculated.

I tried on power6 using xlf/12.1.0.4 with options:
confopts="--enable-fortran --without-xml --without-gsl --without-x "
export CC="xlc_r -q64"
export CXX="xlC_r -q64"
export F77="xlf_r -q64"
export MPICC="mpcc_r -q64"
export AR="ar -X64"
export CPPFLAGS="-I/usr/local/include"
export LDFLAGS="-lmass -lpessl -L/usr/local/lib -lessl"

export OBJECT_MODE=64
export XL_OPTS="-O3 -qhot -qarch=pwr6 -qtune=pwr6"
export CFLAGS="$XL_OPTS -qcpluscmt"
export FFLAGS="$XL_OPTS -qnoprefetch"
export CXXFLAGS="$XL_OPTS"

But also on x86-64 using gfortran (had to change f77 to gfortran in the 
configure):
confopts="--enable-fortran --enable-threads --disable-fftw-measure 
--without-gsl --without-x"

I am actually not interested in the fortran kernels themselves, but in 
the power6 optimized kernels which are in fortran. Since we could not 
get thoose to run (confiugure option  --enable-power6 seems to be turned 
off), I tried the standard fortran kernels.
Is fortran not supported anymore ? What is the fastest option for Power6 
then?



Thanks!

Cheers,
Sebastian