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--- howto:start [2025/03/06 15:28]
kevin
+++ howto:start [2026/02/24 10:42] (current)
ccrosby [Using the Intel compilers]
@@ Line 10: / Line 10: @@
 ===== Tips and Tricks =====
 [[howto:TipsAndTricks|Tips & tricks for common tasks.]] :!: ** Please read this.  The information is based on hard won experience. ** :!:
+===== If you need more memory =====
+As of May 2025, 41 compute nodes have had more memory added, cannibalizing memory modules from nodes that have failed permanently.  These 24-core nodes now have 256 GB of RAM each.  You can access these nodes by including the directive ''mem=250gb'' in your resource request line.  These nodes work with the usual queues such as smp, normal or large.
+<code>
+#PBS -l select=1:ncpus=24:mpiprocs=24:mem=250gb
+</code>
+Only use these nodes if you need more than 128 GB of RAM, but less than the 1TB available on the "fat nodes".
+===== Using the Intel compilers =====
+As of December 2025, there is no license for the Intel Parallel-studio compilers.  However, all is not lost.  The "classic" compilers and MPI are installed in the directory:
+<code>
+/home/apps/chpc/compmech/compilers/intel_2021.3/oneapi
+</code>
+The most recent Lengau-compatible version of the OneAPI suite is installed in:
+<code>
+/home/apps/chpc/compmech/compilers/intel/oneapi
+</code>
+=== Classic Intel compiler and MPI ===
+To use the "classic" suite, use the following settings:
+<code>
+. /home/apps/chpc/compmech/compilers/intel_2021.3/oneapi/compiler/2021.3.0/env/vars.sh
+. /home/apps/chpc/compmech/compilers/intel_2021.3/oneapi/mkl/2021.3.0/env/vars.sh
+. /home/apps/chpc/compmech/compilers/intel_2021.3/oneapi/mpi/2021.3.0/env/vars.sh
+export CC=icc
+export CXX=icpc
+export FC=ifort
+export F90=ifort
+export F77=ifort
+export MPICC=mpiicc
+export MPICXX=mpiicpc
+export MPIFORT=mpiifort
+export MPIF77=mpiifort
+export MPIF90=mpiifort
+</code>
+It is not necessary to use a machinefile for multi-node MPI runs.
+=== OneAPI compilers and MPI ===
+Post-2024 OneAPI compilers are not compatible with Lengau's operating system.  To use the most recent compatible version, use the following settings:
+<code>
+. /home/apps/chpc/compmech/compilers/intel/oneapi/setvars.sh
+export CC=icx
+export CXX=icpx
+export FC=ifx
+export F90=ifx
+export F77=ifx
+export MPICC=mpiicx
+export MPICXX=mpiicpx
+export MPIFORT=mpiifx
+export MPIF77=mpiifx
+export MPIF90=mpiifx
+export I_MPI_HYDRA_BOOTSTRAP=ssh
+</code>
+It is not necessary to use a machinefile for multi-node MPI runs.  However, the default bootstrap method using pbsdsh does not work, hence the need to set ''I_MPI_HYDRA_BOOTSTRAP''.  This is a typical command mpi run command:
+<code>
+mpirun -np 96 myMPIprogram.exe
+</code>

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