[mpich-discuss] Not able to run MPI program parallely...

[Albert Spade]

Hi Pavan,
Thanks for all of your help.
I copied the folder /opt/mpich2-1.4.1p1/bin/bin/ on all of my computer
nodes. And now its working perfectly fine.
So my installation phase is over I suppose. :)

Here is my sample runs with different number of processes. One thing which
I observed and not able to figure out is, as I am increasing the number of
processes the error is decreasing upto 5 processes. But when I run it for
16 processes the error has increased, which I think has to be decreased.
Can you please tell me why this is happening?

Thanks again. And sorry to bother you. :)

[root at beowulf ~]# mpiexec -f hosts -n 1 /opt/mpich2-1.4.1p1/examples/./cpi
Process 0 of 1 is on beowulf.master
pi is approximately 3.1415926544231341, Error is 0.0000000008333410
wall clock time = 0.000220
[root at beowulf ~]# mpiexec -f hosts -n 5 /opt/mpich2-1.4.1p1/examples/./cpi
Process 0 of 5 is on beowulf.master
Process 1 of 5 is on beowulf.node1
Process 3 of 5 is on beowulf.node3
Process 4 of 5 is on beowulf.node4
Process 2 of 5 is on beowulf.node2
pi is approximately 3.1415926544231230, Error is 0.0000000008333298
wall clock time = 0.001994
[root at beowulf ~]# mpiexec -f hosts -n 2 /opt/mpich2-1.4.1p1/examples/./cpi
Process 0 of 2 is on beowulf.master
Process 1 of 2 is on beowulf.node1
pi is approximately 3.1415926544231318, Error is 0.0000000008333387
wall clock time = 0.001151
[root at beowulf ~]# mpiexec -f hosts -n 3 /opt/mpich2-1.4.1p1/examples/./cpi
Process 0 of 3 is on beowulf.master
Process 2 of 3 is on beowulf.node2
Process 1 of 3 is on beowulf.node1
pi is approximately 3.1415926544231323, Error is 0.0000000008333392
wall clock time = 0.001397
[root at beowulf ~]# mpiexec -f hosts -n 4 /opt/mpich2-1.4.1p1/examples/./cpi
Process 0 of 4 is on beowulf.master
Process 1 of 4 is on beowulf.node1
Process 2 of 4 is on beowulf.node2
Process 3 of 4 is on beowulf.node3
pi is approximately 3.1415926544231239, Error is 0.0000000008333307
wall clock time = 0.002573
[root at beowulf ~]# mpiexec -f hosts -n 16 /opt/mpich2-1.4.1p1/examples/./cpi
Process 6 of 16 is on beowulf.node1
Process 11 of 16 is on beowulf.node1
Process 5 of 16 is on beowulf.master
Process 1 of 16 is on beowulf.node1
Process 10 of 16 is on beowulf.master
Process 15 of 16 is on beowulf.master
Process 0 of 16 is on beowulf.master
Process 2 of 16 is on beowulf.node2
Process 8 of 16 is on beowulf.node3
Process 12 of 16 is on beowulf.node2
Process 13 of 16 is on beowulf.node3
Process 7 of 16 is on beowulf.node2
Process 3 of 16 is on beowulf.node3
Process 4 of 16 is on beowulf.node4
Process 14 of 16 is on beowulf.node4
Process 9 of 16 is on beowulf.node4
pi is approximately 3.1415926544231274, Error is 0.0000000008333343
wall clock time = 0.007220
[root at beowulf ~]#
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