HPC Tuning Workshop

Mon, Dec 3  - Wed, Dec 5, 2018 

IT Center 

RWTH Aachen University 

sponsored by:


This year's aiXcelerate HPC Tuning Workshop will focus on the Intel Skylake (SKK) Microarchitecture, SIMD programming and performance tuning using Likwid, Intel VTune/Amplifier and Intel Advisor.

The nodes of CLAIX-2018, the latest RWTH Aachen University’s Supercomputer, are equipped with Intel Skylake processors and connected through a network with the Intel OmniPath architecture (OPA). It is a major extension of CLAIX-2016 system equipped with Intel  Broadwell processors and connected through OPA, too.

Researchers from FZ Jülich and RWTH with high demand for compute power can apply for resources on these systems as part of the JARA-HPC partition (>>> more... ).
Researchers from all over Germany can apply for resources on Claix (>>> more... ).

The workshop will consist of presentations open to a broader auditorium and of a hands-on tuning workshop for a limited number of selected computing projects.
Presentations will be given in English.

We are proud to announce Michael Klemm and Christopher Dahnken, two HPC performance experts from Intel, who will give presentations and support your tuning efforts. Furthermore, a presentation on detecting performance limiting factors with hardware monitoring using likwid will be given by Thomas Gruber (born Röhl) main developer of the Likwid tool. Experts of the HPC Team of the IT Center at RWTH Aachen University will assist in your tuning activietes as well.


  1. Agenda
  2. Sandra Wienke (RWTH): AiXcelerate Welcome & CLAIX-2018 Overview
  3. Marcus Wagner, Paul Kapinos (RWTH): SLURM and Modules for CLAIX-2018
  4. Jonas Hahnfeld (RWTH): Performance Monitoring on CLAIX
  5. Michael Klemm (Intel): Skylake Architecture
  6. Michael Klemm (Intel): Skylake Performance Considerations
  7. Michael Klemm (Intel): Intel VTune Amplifier
  8. Thomas Gruber (FAU Erlangen): LIKWID, Detecting Performance Limiting Factors with Hardware Monitoring


Please  register here for any or all presentations.

aiXcelerate 2018 - Presentations

  1. Dec 3, 11:00-13:00 - On Mon morning, Dec 3, we will start at 11:00 with presentations on the new CLAIX-2018 cluster and the Skylake processor microarchitecture
  2. Dec 3, 14:00-15:00 - After lunch on Monday, we will continue with presentations on SIMD programming and performance optimisation.
  3. Dec 4, 11:00-13:00 - On Tuesday morning, Dec 4, we will start at 11:00 with presentations on Likwid, Intel VTune/Amplifier and Advisor.

aiXcelerate 2018 - Tuning Workshop

After the presentations on Mon Dec 3, on Tue Dec4, and also throughout Wed, Dec 5, we provide you with hands-on opportunity to adapt, analyze and tune your performance critical applications on CLAIX, with its Skylake (and Broadwell) processors connected with the Intel OmniPath (OPA) fabric.

Participation in the presentations is a prerequisite for participation in tuning workshop.

Attendees are kindly requested to prepare and bring in their own code. It is assumed that you have a good working knowledge with MPI and/or OpenMP, and C/C++ or Fortran, whatever your compute project employs. To maximize the efficiency of the workshop, we would like to ask you to prepare one or more test cases that reflect typical production runs, but do not take too long to execute - in the ideal case, a run should not take more than 5 to 10 minutes to finish. Members of the local HPC team will support  every accepted project in porting the code to Claix. By the start of the workshop the code should be ready to be analyzed.

Furthermore, each participant (or participating group) is kindly asked to shortly present their project (1-2 slides) at the beginning of the tuning workshop and also shortly present the outcome of the tuning efforts at the end of the workshop.

If you are intested to participate in the tuning activities please contact us by sending an email to hpcevent@itc.rwth-aachen.de.

Workshop participants are invited to take part in the social dinner on Tuesday, Dec 4 in the restaurant Palladion.



Attendance is free of charge and supported by our sponsors.
Travel and accommodation are at your own expense.

Links to previous Events 

Travel Information

If required, please make your own hotel reservation.You can find some popular hotels listed here. You may find a complete list of hotels on the web pages of the Aachen Tourist Service. We recommend that you try to book a room in the "Novotel Aachen City", " Mercure am Graben" or "Aachen Best Western Regence" hotels. These are adequate hotels with reasonable prices at a walking distance (20-30 minutes) to the IT Center through the old city of Aachen. An alternative is the hotel "IBIS Aachen Marschiertor" which is close to the main station, which is convenient if you are travelling by train and also want to commute to the IT Center by train (3 trains per hour, 2 stops)

Please, download a sketch of the city (pdf, 415 KB) with some points of interest marked.
You may find a description of how to reach us by plane, train or car here.
Bus route 33 connects the city and the stop "Mies-van-der-Rohe-Straße" every 15 minutes.
Trains between Aachen and Düsseldorf stop at "Aachen West" station which is a 5 minutes walk away from the IT Center.
From the bus stop and the train station just walk uphill the "Seffenter Weg". The first building on the left hand side at the junction with "Kopernikusstraße" is the IT Center.

The weather in Aachen is usually unpredictable. It is always a good idea to carry an umbrella. If you'll bring one, it might be sunny!

Technical Information for Tuning Workshop Participants

Workshop participants should have an account at the HPC Cluster in Aachen. In case you do not bring in your own laptop we can provide a lend device for you; in this case please be equipped also with the 'PC Pool' account (get it via Selfservice).

Please contact us and send us your HPC account (like ab123456) so we can add you to the project "hpclab" for the workshop.




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