Howto - Run Intel Xeon Phi Calculations
The dogmatix? nodes smp-6-0, smp-6-1, smp-6-2, smp-6-3 and smp-6-7 each have 2 x Intel Xeon Phi coprocessor 7120P each with 61 physical cores at 1.238 GHz, 16GB RAM @ 352 GB/s. They burn up 300 Watts. The Intel Many Integrated Core Architecture or Intel MIC is an x86-compatible multiprocessor architecture with OpenMP, OpenCL,Cilk/Cilk Plus support through Intel's Fortran, C++ compilers and the Intel MKL.
Specs and status of the Phi
To examine the specs and status of the Phi/s once you've logged into a node (using srun) use the micinfo command.
There is also the GUI tool micsmc available on the nodes.
Compiling for the Phi
To run natively on the intel phi mics use the intel compiler and add the -mmic option to the command line arguments:</p>
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module load intel
icc -mmic ...
ifc -mmic ...
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For more information about developing code for the phi mics see the intel guide.
Mic access
Access to the mics is by ssh using public key authentication. For this to work with submitted jobs you need to generate a ssh key pair with an empty password:</p> @@
ssh-keygen -t rsa -N ''
@@ Then add the generated public key .ssh/id_rsa.pub to your .ssh/authorized_keys file.
Submitting jobs
You can submit a job to run on a single mic with a script like:</p> @@
- SBATCH --gres=mic:1
#SBATCH --time=01:00:00
#SBATCH --mem=1G
ssh -x mic${OFFLOAD_DEVICES} "bash -l -c path_to_executable_ _arguments"
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Automatic offload
Automatic offload is another way to use the phi mics. For example some intel MKL libraries will use automatic offload if they detect an available mic. See the intel guide for more information.