Dear All,<br /><br />&nbsp;&nbsp;&nbsp; Could anyone tell me the important tuning parameters in openmpi with IB interconnect? I tried setting eager_rdma, min_rdma_size, mpi_leave_pinned parameters from the mpirun command line on 38 nodes cluster (38*2 processors) but in vain. I found simple mpirun with no mca parameters performing better. I conducted test on P2P send/receive with data size of 8MB.<br /><br />&nbsp;&nbsp;&nbsp; Similarly i patched HPL linpack code with libnbc(non blocking collectives) and found no performance benefits. I went through its patch and found that, its probably not overlapping computation with communication.<br /><br />Any help in this direction would be appreciated.<br />-Neeraj<br />
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