[CPMD-list] Itanium SGI

[Axel Kohlmeyer]

On Tue, 2 Nov 2004, Eliana K Asciutto wrote:

dear eliana,

could you please elaborate a little on the 'network' on 
that cluster, i.e. is this a traditional 'cluster' with
ethernet or some faster interconnect like SCI, myrinet, 
or infiniband. or is this on of those single-system-image
SMP-like altix machines? how fast are the cpus? how much
cache do they have? (check out the contents of /proc/cpuinfo).

if you have SMP-nodes, you may want to try setting the 
environment variable OMP_NUM_THREADS to 1 for all instances
or your job. AFAIK, the some part of the MKL does spawn
as many threads as there are SMP-cpus. in combination with
MPI this can be very counterproductive. 

also, performance may depend on the load. do you have the
machine exclusively?

your compilation flags seem ok.

regards,
	axel.

EA> Dear all,
EA> 
EA> I've compiled succesfully CPMD 3.9 in a SGI Itanium cluster.
EA> The problem is that it is very slow (compared with an Intel Xeon 
EA> cluster). Perhaps I'm missing some compilation's option  in order to 
EA> speed it up.
EA> Here is my Makefile:
EA> 
EA> 
EA> 
EA> #--------------- Default Configuration for SGI_LINUX_IA64_INTEL-MPI 
EA> ---------------
EA> SRC  = .
EA> DEST = .
EA> BIN  = .
EA> #QMMM_FLAGS = -D__QMECHCOUPL
EA> #QMMM_LIBS  = -L. -lmm
EA> FFLAGS = -fpp -D__alpha -DPOINTER8 -DLAPACK -DFFT_DEFAULT -DALPHALINUX \
EA>         -DPARALLEL=parallel -DMP_LIBRARY=__MPI -DLINUX_IA64_INTEL \
EA>         $(shell date +'-D__DATE__=\""%b %e %Y"\" -D__TIME__=\"%T\"')
EA> LFLAGS = -L/opt/intel/mkl70/lib/64 -lmkl_itp -lmkl_lapack -lmkl_itp \
EA>              -lPEPCF90 -lm -lpthread -lmpi $(QMMM_LIBS)
EA> CFLAGS = -DPGSIZE="getpagesize()" -D__alpha -DPOINTER8 -DLAPACK 
EA> -DFFT_DEFAULT -DALPHALINUX \
EA>         -DPARALLEL=parallel -DMP_LIBRARY=__MPI -DLINUX_IA64_INTEL
EA> CPP = /bin/cp --remove-destination
EA> CPPFLAGS =
EA> NOOPT_FLAG =
EA> CC = gcc -O2 -c -Wall
EA> FC = efc -O2 -w -w90 -w95 -cm -c
EA> LD = efc -O2
EA> AR = /usr/bin/ar -r
EA> 
EA>  
EA> Any suggestions?
EA> Thanks,
EA> 
EA> Eliana
EA> 
EA> 
EA> 

-- 

=======================================================================
Dr. Axel Kohlmeyer   e-mail: axel.kohlmeyer at theochem.ruhr-uni-bochum.de
Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
D-44780 Bochum  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.