==== Process pinning ====

The NUMA memory of VSC-2 is highly depending on the positioning of processes to the four ''NUMA nodes'' on each compute node. 
Using Intel MPI the Parameter
<code>export I_MPI_PIN_PROCESSOR_LIST=1,14,9,6,5,10,13,2,3,12,11,4,7,8,15,0
</code>
as mentioned above should always be used to pin (up to) 16 processes to the 16 cores.
In the case of sequential jobs, we recommend to use 'taskset' or 'numactl', e.g.
<code>
taskset -c 0 our_example_code param1 param2 >out1 &
taskset -c 8 our_example_code param1 param2 >out2 &
wait
</code>
Performance gains of up to 200% were observed for synthetic benchmarks.
Note also the examples for [[sequential-codes|sequential jobs]].