[mvapich-discuss] Same nodes different time?

[Daniel WEI]

Dear List,

Is it possible that:

hosts (1):
node1:16
node2:16
node3:16
node4:16

gives a different results than

hosts (2):
node2:16
node4:16
node3:16
node1:16

I mean does the node sequence appears in the hostfile matter (suppose
node1~node4 are exactly the same architecture) concerning the speed?

If I use simple mpirun -np XX blahblah, how mvapich2 generated this node
sequence? Based on what? Which node is going to be the host node, which are
going to be the slave nodes? Is it a random decision?

My simulation go different wall clock time at the end of 100 time steps of
my simulations, the residuals and everything is the same, I have checked of
the log and the results, it is just the time taken for each time step is
different. Is it a memory issue or oversubscription issue? Has anyone
experience this situation before?


Thanks a lot,




Zhigang Wei
----------------------
*University of Notre Dame*
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