[OMPI users] slow MPI_BCast for messages size from 24K bytes to 800K bytes.

ow if you need any more information from my side. thanks for your time, Krishna Muriki, HPC User Services, Scientific Cluster Support, Lawrence Berkeley National Laboratory. I) Payload size 8M bytes over IB: [kmuriki@n0005 pub]$ mpirun -v -display-map --mca btl openib,self -np 4 -hostfile hostfi

Re: [OMPI users] slow MPI_BCast for messages size from 24K bytes to 800K bytes.

thanks for your time, Krishna Muriki, HPC User Services, Scientific Cluster Support, Lawrence Berkeley National Laboratory. I) Payload size 8M bytes over IB: [kmuriki@n0005 pub]$ mpirun -v -display-map --mca btl openib,self -np 4 -hostfile hostfile.lr ./testbcast.800 [n0005.scs00:13

Re: [OMPI users] slow MPI_BCast for messages size from 24K bytes to 800K bytes. (fwd)

Hi Jeff, Please read below: On Jan 12, 2009, at 2:50 PM, kmur...@lbl.gov wrote: Is there is any requirement on the size of the data buffers I should use in these warmup broadcasts ? If I use small buffers like 1000 real values during warmup, the following actual and timed MPI_BCAST over IB is

Re: [OMPI users] slow MPI_BCast for messages size from 24K bytes to 800K bytes. (fwd)

Hi Jeff, Here is the code with a warmup broadcast of 10K real values and actual broadcast of 100K real*8 values(different buffers): [kmuriki@n pub]$ more testbcast.f90 program em3d implicit real*8 (a-h,o-z) include 'mpif.h' ! em3d_inv main driver ! INITIALIZE MPI AND DETE

Re: [OMPI users] How to know which task on which node

Hi Gaurav, Try using the -display-map option with mpirun command. I use it and it gives me the nodes listing along with MPI tasks running on those nodes. --Krishna. On Mon, 19 Jan 2009, gaurav gupta wrote: Hello, I want to know that which task is running on which node. Is there any way to k