[mpich-discuss] Scalability of Intel quad core (Harpertown) cluster

[Elvedin Trnjanin]

You would do that within the code. If you're trying to pass every 
element of an int array one at a time (message size is sizeof(int)), it 
will have much worse performance than sending the entire array (message 
size is sizeof(int)*arraydimensions.

Example - 
http://www.scl.ameslab.gov/Projects/mpi_introduction/figs/mpi_pong.c
This is a start for a decent approximation of network bandwidth and 
latency for a certain message size. Although not accurate, it'll 
certainly give you an idea of your network's performance with various 
message sizes and transfer types. It only works on two nodes at a time 
however so other types of communication like AlltoAll are not tested.

Hee Il Kim wrote:
>
> I checked the bandwidth behavior mentioned by Elvedin. Could I change 
> or setup the message size and frequency in a runtime level or any 
> other steps?
>