🎓 Hybrid Programming in HPC – MPI+X

Most HPC systems are clusters of shared memory nodes and many use accelerators, e.g. GPUs. 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 with and without accelerators. Multi-socket-multi-core systems, with and without accelerators, in highly parallel environments are given special consideration. In addition, we will review the shared memory programming interface introduced in MPI-3.0, which can be combined with inter-node MPI communication.

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.

This course is a joint training event of SIDE and EuroCC-Austria, the German and Austrian National Competence Centres for High-Performance Computing. It is organized by the HLRS in cooperation with the ASC Research Center, TU Wien and NHR@FAU.

Prerequisites:

• Participants are expected to be familiar with basic MPI and OpenMP programming since this course is not for beginners in parallel programming. Minimum requirements is that you are familiar with the topics of days one and two at https://fs.hlrs.de/projects/par/events/2022/agenda_2022-PAR.pdf. You are well prepared if you attended our HLRS courses on MPI and OpenMP for instance.
• For the hands-on sessions you should know Unix/Linux and either C/C++ or Fortran.
• The hands-on labs will be done on a cluster at HLRS, all participants will get a training user account for the duration of the course.

Content levels:

• Advanced: 13:45 hours

Learning outcomes

This course provides scientific training in Computational Science, focusing on hybrid programming techniques to efficiently optimize memory usage and communication on multi-core, multi-socket HPC systems, with and without accelerators.

------- PRELIMINARY AGENDA -------

1st day – Tuesday, 10 February 2026

10:45   Join in
11:00      Welcome
11:15      Introduction to Hybrid Programming in HPC – MPI+X
11:45      Programming Models
11:50         - MPI + MPI-3.0 Shared Memory
12:30   Lunch
14:00         - MPI + OpenMP lecture and hands-on - how to compile and start
15:15   Break
15:30         - MPI + OpenMP lecture and hands-on - how to do pinning
16:45     Q & A
17:00   End of first day

2nd day – Wednesday, 11 February 2026

08:45   Join in
09:00         - continue: MPI + OpenMP
09:00         - Case study: Simple 2D stencil smoother
09:30            Hands-on - hybrid through OpenMP parallelization
10:45   Break
11:00         - Overlapping Communication and Computation
11:30            Hands-on - taskloops
12:15         - MPI + OpenMP Conclusions
12:30   Lunch
14:00         - MPI + Accelerators lecture and hands-on
15:15   Break
15:30         - MPI + Accelerators lecture and hands-on
16:45           Q & A
17:00   End of second day

3rd day – Thursday, 12 February 2026

08:45   Join in
09:00      Programming Models (continued)
09:05         - MPI + Accelerators lecture and hands-on
10:30   Break
10:45         - MPI + Accelerators lecture and hands-on
11:45   Break
12:00      Conclusions, Q & A, Feedback
13:00   End of third day (course)

Handout

A link to the course material (slides and exercises) will be available at course start

Fees

Students without Master's degree or equivalent. Participants from EU or EuroCC countries only: 0 EUR
PhD students or employees at a German university or public research institute: 0 EUR
PhD students or employees at a university or public research institute in an EU or EuroCC country other than Germany: 0 EUR.
Other participants, e.g., from industry, other public service providers, or government. Participants from EU or EuroCC countries only: 0 EUR

Our course fee includes coffee breaks (in classroom courses only).

For lists of EU and EuroCC countries have a look at the Horizon Europe and EuroCC website.

Only participants from institutions belonging to these countries can take part in this course.