PASC conference

The Platform for Advanced Scientific Computing (PASC) conference is a popular event for sharing the latest developments and findings in the field of computational sciences. Held each year in Switzerland, this year PASC will return to Zurich under the theme Synthesizing Applications Through Learning and Computing. With a general focus this year on the grand challenge of combining physics-based simulations with novel machine learning and AI based methods to address interdisciplinary problems in science, PASC always attracts a very wide ranging audience and is an excellent way in which traditionally disparate fields can connect.

A major component of PASC are the mini-symposia, which is a two hour session focussed on a specific topic. Combining technical talks with panels, these enable world experts in a specific topic to connect with the wider PASC audience to discuss how these fields can be leveraged by the wider scientific computing community most effectively.

There will be two ExCALIBUR mini-symposia at PASC24 this year, the first is Modern PDE discretisation methods and solvers in a non-smooth world which will be led by Tobias Weinzierl (MGHyPE (phase 2) project) and Eike Mueller, as well as other talks being given more widely.

This minisymposium will explore the tension between high-order discretisation methods for PDEs and the fact that many physical phenomena are non-smooth. It will consist of talks by Marc Marot-Lassauzaie (TU Munich), Jemma Shipton (Exeter and part of the ExCALIBUR parallel in time and RSE training projects) and Olindo Zanotti (Trento); a discussion session will explore how the advantages of sophisticated PDE solvers and Machine Learning can be combined productively.

High order discretisations in space and time can make optimal use of FLOP-bound exascale hardware and have the potential to unlock additional parallelism. However, it is an open question how these methods can be applied to time-dependent PDEs with elliptic constraints. Off-the-shelf preconditioners are not sufficient and multigrid methods are being developed to solve the resulting large sparse linear systems of equations. Implementing advanced reliable and performance portable PDE based simulation tools  requires the combined expertise of specialists from different domains. Real-life codes are starting to use novel discretisation techniques: the UK Met Office explores the solution of the equations of atmospheric fluid dynamics with hybridised finite elements, non-nested multigrid preconditioners and parallel-in-time methods. The ADER-DG ExaHype engine is being extended to include elliptic constraints and support implicit timestepping for astrophysics simulations.

The other mini-symposium is Riding the Cambrian explosion in hardware for scientific computing and this has been organised by the RISC-V, CGRA, and PETSc for CS-2 H&ES testbeds. This session will focus on exploring the potential of the plethora of new hardware that is coming available (much of it driven primarily by AI workloads) for accelerating HPC applications. It will consist of talks by Teresa Cervero Garcia (Barcelona Supercomputing Centre) who is an expert on RISC-V and will be discussing the role of this technology in HPC, Artur Podobas (KTH) who is an expert on Coarse Grained Reconfigurable Architectures (CGRAs) and will be reflecting on whether these are likely to be usable for HPC, and Joseph Lee (EPCC) who has used the Cerebras CS-2 extensively and will be sharing his experiences.

George Bisbas from the ExCALIBUR xDSL project will be giving a presentation in the Motif-Based Automated Performance Engineering for HPC mini-symposium about work done in this project enabling Devito to leverage the MLIR ecosystem. Describing how structured-grid based abstractions in Python are lowered to highly efficient parallel code, George will highlight the benefits that MLIR provides when it comes to sharing common compiler infrastructure and introduce the xDSL framework that lowers the barrier to entry in leveraging this compiler technology.

There will be many other sessions also going on at PASC, with the schedule released soon. So a great opportunity to catch up with the latest developments in scientific computing and HPC.