[CPMD-list] CPMD on 64-bit Linux (openSUSE 10.3) Intel Xeon

[Axel Kohlmeyer]

On Mon, 7 Apr 2008, oksana ismailova wrote:

OI> Dear  Axel and  Reuti!
OI> 
OI> 
OI> Thanks a lot for your  prompt responses and helps.
OI> 
OI> these options in the Makefile
OI> worked:
OI> FFLAGS = -pc64 -O2 -unroll
OI> LFLAGS = -L/opt/intel/mkl/10.0.2.018/lib/em64t -lmkl_sequential 
OI> -lmkl_lapack
OI> -lmkl_em64t -lguide ­lpthread

ok. there is some room for optimization, though. 
the cleaner solution with the best performance would be:

FFLAGS= -O2 -unroll -pc64 -march=pentium3 -mtune=core2 
LFLAGS= -L/opt/intel/mkl/10.0.2.018/lib/em64t -lmkl_intel_lp64 -lmkl_sequential -lmkl_core

this will link with the non-openmp version of the libraries
and thus no -lpthread or -lguide should be needed.

with intel MKL v10 this is required unless you set 
OMP_NUM_THREADS to 1 in your default environment.

additional speedup can be achieved by using FFTW instead of the
default internal default FFT. for that you'll have to install 
fftw-2 (not fftw3!), change -DFFT_DEFAULT to -DFFT_FFTW and
add -ldfftw (or -lfftw depending on your Linux) to LFLAGS.
the major source for the speedup is actually less the speed
of the FFT different implementations, but the fact that FFTW
supports more grids, so you may find a smaller grid that
fits your problem and thus reduces the amount of data to be
processed (and the memory needed).

cheers,
   axel.

OI> Based on IFORT-AMD64
OI> 
OI> 
OI> dear cpmd users,
OI> any ideas or help will be appreciated
OI> 
OI> Our system administrator asks  me pass on his thanks also.
OI> 
OI> best regards,
OI> oksana
OI> 
OI> 
OI> 
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-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.