In the last few decades, various numerical codes have emerged to tackle complex astrophysical problems. Usually, these codes are designed for parallelization on tens to millions of CPU cores. However, the current High-Performance Computing ecosystem is shifting towards new hybrid accelerated machines to reach both exascale performance and meet energy sobriety requirements.

The ability to use such accelerated systems is therefore crucial to access large-scale, French and European supercomputers. However, the use of GPU architectures in astrophysics is largely under-exploited, revealing a pressing need for accelerated codes.

In this context, the IDEFIX code was designed to provide a user-friendly framework to run fluid simulations in parallel, both on CPU and GPU devices. It uses the metaprogramming library KOKKOS to remain highly performant while being portable.

The code is publicly available on GitHub.

The aim of this 2nd edition of the IDEFIX user days is to gather a community of astrophysicists that already use or wish to use the IDEFIX code. The program will include hands-on tutorials (about the new IDEFIX modules, visualisation tools, use on national clusters, development) for new and current users. This first call for registration of interest will help us to evaluate the desired level of the tutorials and the need for possible splinter sessions. We will also have plenary sessions to promote the new features of IDEFIX, its current applications, as well as defining a roadmap for future developments. This last part is especially important since the IDEFIX User Days are the best opportunity for us to identify user needs and determine areas of development for IDEFIX.

Geoffroy Lesur

Jonah Mauxion

Nicolas Scepi

Marc Van den Bossche

Gaylor Wafflard-Fernandez