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Last modified by valad on 2024/05/28 10:16
From version 2.1
edited by Thomas Coelho
on 2023/02/27 14:52
Change comment: There is no comment for this version
To version 5.1
edited by valad
on 2024/05/28 10:09
Change comment: There is no comment for this version

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1 -XWiki.thw
1 +XWiki.valad
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6 6  
7 7  Bash users can add the following lines to their .bashrc:
8 8  
9 -{{{export OMPI_FC='ifort'
10 -export OMPI_F77='ifort'
11 -export OMPI_CC='icc'}}}
9 +{
12 12  
11 +{{export ompi_fc='ifort'
12 +export ompi_f77='ifort'
13 +export ompi_cc='icc'/}}
13 13  
15 +}
14 14  
15 -Especially if you use icc, it will be better if you use the recent [[Intel Compiler 11.0>>Intel_Compiler_Temp]].
17 +Especially if you use icc, it will be better if you use the recent ~[~[Intel Compiler 11.0>>Intel_Compiler_Temp]].
16 16  
17 17  == Infiniband ==
18 18  
19 19  The 'itp'-, 'itp-big'-, 'dfg-xeon'-, 'iboga'-, 'dreama'- and 'barcelona'-nodes have Infiniband Network. It is used by default when using our openMPI installation. Infiniband provides high bandwith with low latency. It can transport 20 GB/s with latency of 4 µs. In comparison, normal Gigabit Ethernet provides 1 GB/s with at least 30 µs latency. Latency is the time a data packet needs to travel from the source to its target. This is the main drawback when using Gigibit Ethernet for MPI communication.
22 +
23 += Mellanox HPCX =
24 +
25 +Mellanox is the manufacturer of our Infiniband hardware. They provide an optimized set of libraries for running parallel programs.
26 +
27 +With the recent update to Ubuntu 18.04 some programs failed with the system default openMPI library. As alternative we have installed a system wide HPCX software.
28 +
29 +This lives in
30 +
31 +{{{ /home/software/hpcx/current .}}}
32 +
33 +This points to the latest installed version.
34 +
35 +To use this library you have to extend your .bashrc. Include the following lines:
36 +
37 +{{{export HPCX_HOME=/home/software/hpcx/current
38 +source $HPCX_HOME/hpcx-init.sh}}}
39 +
40 +This doesn't change your actual environment yet. To finally activate the setup call:
41 +
42 +{{{hpcx_load}}}
43 +
44 +Then all MPI tools are loaded from HPCX. This is required for building and running. You may call this is in your jobs-scripts.
45 +
46 +There are other MPI flavours in HPCX. Read the documentation within there:
47 +
48 +{{{/home/software/hpcx/current/README.txt
49 +}}}