Topic outline

  • Partnership for Advanced Computing in EuropeImportant note:

    The course agenda and materials shown below are those of the 2022 ONLINE EDITION of the course.

    All materials will be updated right before the next course takes place at LRZ.



    Most HPC systems are clusters of shared memory nodes. To use such systems efficiently both memory consumption and communication time has to be optimized. Therefore, hybrid programming may combine the distributed memory parallelization on the node interconnect (e.g., with MPI) with the shared memory parallelization inside of each node (e.g., with OpenMP or MPI-3.0 shared memory). This course analyzes the strengths and weaknesses of several parallel programming models on clusters of SMP nodes. Multi-socket-multi-core systems in highly parallel environments are given special consideration. MPI-3.0 has introduced a new shared memory programming interface, which can be combined with inter-node MPI communication. It can be used for direct neighbor accesses similar to OpenMP or for direct halo copies, and enables new hybrid programming models. These models are compared with various hybrid MPI+OpenMP approaches and pure MPI. Numerous case studies and micro-benchmarks demonstrate the performance-related aspects of hybrid programming.

    Hands-on sessions are included on all days. Tools for hybrid programming such as thread/process placement support and performance analysis are presented in a "how-to" section. This course provides scientific training in Computational Science, and in addition, the scientific exchange of the participants among themselves.

    Content Levels: Beginners = 0:00h (0%) + Intermediate = 1:30h (10%) + Advanced = 13:30h (90%)

    Prerequisites: Basic MPI and OpenMP knowledge as presented in the VSC courses on MPI and OpenMP.
                             For the hands-on sessions you should know Unix/Linux and either C/C++ or Fortran.

    This online course is a PRACE training event. It is organised by LRZ in cooperation with HLRS, NHR@FAU and the VSC Research Center, TU Wien.

    Agenda & Content

    1st day – 22 June 2022

    08:45   Join online
    09:00    Welcome
    09:05    Motivation
    09:15    Introduction
    09:30    Programming Models
    09:35       - MPI + OpenMP
    10:00          Practical (how to compile and start)
    10:30   Break
    10:45       - continue: MPI + OpenMP
    11:30   Break
    11:45        - continue: MPI + OpenMP
    12:30          Practical (how to do pinning)
    13:00   Lunch - (Co)-Hosts not available
    14:00          Practical (hybrid through OpenMP parallelization)
    15:30          Q & A, Discussion
    16:00   End of first day

    2nd day – 23 June 2022

    08:45   Join online
    09:00       - Overlapping Communication and Computation
    09:30          Practical (taskloops)
    10:30   Break
    10:45       - MPI + OpenMP Conclusions
    11:00        - MPI + Accelerators
    11:30    Tools
    11:45   Break
    12:00    Programming Models (continued)
    12:05       - MPI + MPI-3.0 Shared Memory
    13:00   Lunch - (Co)-Hosts not available
    14:00          Practical (replicated data)
    15:30          Q & A, Discussion
    16:00   End of second day

    3rd day – 24 June 2022

    08:45   Join online
    09:00       - MPI Memory Models and Synchronization
    09:40       - Pure MPI
    10:00   Break
    10:15        - Recap - MPI Virtual Topologies
    10:45       - Topology Optimization
    11:15   Break
    11:30          Practical/Demo (application aware Cartesian topology)
    12:30       - Topology Optimization (Wrap up)
    12:45     Conclusions
    13:00   Lunch - (Co)-Hosts not available
    14:00     Finish the hands-on labs, Discussion, Q & A, Feedback
    16:00   End of third day (course)


    Date: Wednesday, June 22, 2022, 08:45 - Friday, June 24, 2022, 16:00
    Location: ONLINE COURSE @ LRZ
    Language:    English


    Georg Hager (NHR@FAU), Rolf Rabenseifner (HLRS), Claudia Blaas-Schenner (VSC Research Center, TU Wien)

    Course material (here ☺) :   

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  • Training Events (further courses)

      VSC Vienna:              

      HLRS Stuttgart:       

      LRZ Garching/Munich:


      NHR Alliance:            

      PRACE Training Portal: