Hi,
I noticed that the exact same code took 50% more time to run on OpenMPI
than Intel. I use the following syntax to compile and run:
Intel MPI Compiler: (Redhat Fedora Core release 3 (Heidelberg), Kernel
version: Linux 2.6.9-1.667smp x86_64**
mpiicpc -o xxxx.cpp <filename> -lmpi
OpenMPI 1.4.3: (Centos 5.5 w/ python 2.4.3, Kernel version: Linux
2.6.18-194.el5 x86_64)**
mpiCC xxxx.cpp -o <filename
MPI run command:
mpirun -np 4 <filename>
**Other hardware specs**
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 3
model name : Intel(R) Xeon(TM) CPU 3.60GHz
stepping : 4
cpu MHz : 3591.062
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 5
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
pge mca cmov pat pse36
clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lmconstant_tsc
pni monitor ds_cpl est tm2
cid xtpr
bogomips : 7182.12
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:
Can the issue of efficiency be deciphered from the above info?
Does the compiler flags have an effect on the efficiency of the
simulation. If so, what flags maybe useful to check to be included for
Open MPI.
Will including MPICH2 increase efficiency in running simulations using
OpenMPI?
Thanks,
Ashwin.
