Intel® Clusters and HPC Technology

Problem with intel mpi: same job 6x slower on 4 cores of 1 node than on 2 cores of 2 nodes


We have a small linux cluster Oscar/CentOS 5.5: a master and 4 nodes. We are computing only on the nodes. The nodes are identical: 2 hexacores X5650 (so 2*6 cores per node). There are 24 Gb of RAM per nodes. All the cluster is connected with infiniband and the driver of open linux fabrics is used. The intel cluster Toolkit is installed on the master and on all the nodes.

How to get started with Intel MPI

I am trying to use MPI. I have Windows 7 with 64 bit and Intel

Fortran with Microsoft Visual Studio 2008. I have already installed
Intel MPI Library 4.0 but don't know how to use it. I went to my
project' property page and add \\em64t\\include to the
include path and \\em64t\\lib to the library path. But when
I compile the project, I receive error messages such as "unresolved
external symbol main_init referenced in function". Could anybody help

Thank you.


How to debug under Intel MPI?


How to set a breakpoint on a given rank? In the following example, I would like to set a breakpoint on rank0, but not on rank 1 and rank2. how do I do it? How do I switch between different rank? Thanks.

[linfa@ran testrun]$ mpirun -gdb -np 3 ../exec/intelmpitest
WARNING: Can't read mpd.hosts for list of hosts, start only on current
0-2: (gdb)


VAST-F/toOpenMP vs Intel fortran compiler auto-parallelization

Could you sombody who knows the VAST-F/openMP tool compare it with PGI fortran compiler auto-parallelization feature from the computing performance point of view?

More info about VAST-F/toOpenMP is here:

and here

Some fortran gurus recommend this tool as a superior OpenMP parallelizer on source code level!?

Intel MPI and torque integration: the "elapsed time" displayed under torque is always 00:00


We have a little cluster with Oscar/CentOS 5.5. We are using torque and the Intel Cluster Toolkit. Torque and the ICT are configured and Jobs are running without problem at the moment. But the "elapsed time" displayed by Torque with a "qstat -a" is always 0. :'(

If we switch to openmpi, the elapsed time of the the running jobs are correctly updated.

Is this a known issue ? is there a solution ?

Best regards,

OpenMp turncation error

OpenMp turncation error
Im quite new to
openMP and I found that the results of the serial and parallel version
of the following code has a difference at the last decimalplace.

I use intel fortran compiler in an intel 64 bit machine under fedora 10.

Can anybody pls tell me a way how can this be elminated.

program main
implicit none
integer i,j,l
double precision a(9999)

IMPI with on any Debian (for ex. Ubuntu)?

Dear Intel,

I've been using your compiler several years with a big pleasure.

I'm continue developing my skills as you continue to improve your development tools and compilers.

Thank you for that!

My question is how I can recompile all my projects with Intel MPI. I put some parallelization and want to simulate mpirun on my centrino + Ubuntu.

problem with intel mpi 4.0

Dear all,

I have a program to call intel mpi's functions. The program seems good but some times after finished running, the following error message popped up:
Fatal error in MPI_Comm_free: Invalid communicator, error stack: MPI_Comm_free(134): MPI_Comm_free(comm=00000001403B600) failed
MPI_Comm_free(105): Cannot free permanent communicator MPI_COMM_WORLD.

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