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seminaire passé

[SEMINAR] March 2019 – Emulating quantum computers 🧑‍🏫 Victor Alessandrini

🧑‍🏫 Victor Alessandrini, Maison de la Simulation, France
🌎 March 2019

Abstract:

There is today increasing consensus on the fact that quantum computing – an emerging data processing technology – may in the future play a significant role (with not yet fully understood boundaries) in high performance scientific computing. The simulation of quantum computers on standard computing platforms is today a necessary step to understand, assess, and develop quantum algorithms for computation, paving the way for the eventual future adoption of this disruptive technology. Emulation software will remain useful for some time to validate results of the earlier quantum computing platforms, and to help tuning application quantum codes. We will present a fully portable C++ emulation library under development for more than one year. The library disposes of three interfaces: a shared memory version running on SMP nodes, a MPI extension enabling access to a larger number of qubits, and a Python wrapper of the C++ library. A significant pedagogical effort is implemented in the documentation. Besides the traditional C++ class documentation, we are producing strategic higher level documentation and pedagogical papers on applications, including Jupyter notebooks. This seminar will propose first an introduction to quantum computing, explaining the fundamental differences with classical computing, underlining the strong features as well as the limiting bottlenecks of the technology. We will present next a short and very high level overview of the emulation library, focusing on a few major strategic choices. Then, the issues involved in quantum algorithms will be illustrated with a quantum chemistry example used in the validation tests of the software. Finally, we will conclude with a rapid overview of different areas in which quantum algorithm research is evolving (quantum chemistry, condensed matter physics, combinatorial optimization, fault tolerant quantum computing,…).

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Non classé seminaire passé

[SEMINAR] February 2019 – Hercules 🧑‍🏫 Olivier Bressand

🧑‍🏫 Olivier Bressand, CEA-DAM, France
🌎 February 2019

Abstract

Hercules is a CEA-DAM platform for managing data produced by simulation codes. It integrates different I/O services to read, write in parallel database in the framework of protection / recovery, intercode (coupling or code sequence) and post-processing (visualization and analysis). It is based on a data model that covers many domains of simulation (structured, unstructured, AMR-block, AMR-tree based, multi-fluid, laser, atom, Euler, Lagrange, ale, 1D, 2D, 3D) and provides services to produce, filter, and disaggregate data in the sequential or parallel HPC application.

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Non classé seminaire passé

[SEMINAR] February 2019 – MPC, The Multi-Processor Computing Framework 🧑‍🏫 Julien Jaeger

🧑‍🏫 Julien Jaeger, CEA-DAM, France
🌎 February 2019

Abstract

The MPC (Multi-Processor Computing) framework provides a unified parallel runtime designed to improve the scalability and performances of applications running on clusters of (very) large multiprocessor/multicore NUMA nodes. Thanks to its design, MPC allows mixed-mode programming models and efficient interaction with the HPC software stack. MPC provides implementations for the MPI, OpenMP and POSIX Threads standards. All these standards can be mixed together in an efficient way, thanks to process virtualization, and the sharing of information and resources

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seminaire passé

[SEMINAR] February 2019 – PaDaWan 🧑‍🏫 Julien CAPUL

🧑‍🏫 Julien CAPUL, CEA-DAM, France
🌎 February 2019

PaDaWAn is an infrastructure providing in-memory data exchange between applications and a simple configuration model to switch from a file-based workflow to an in-transit workflow. The infrastructure is currently based on CEA-DAM Hercule parallel I/O libray by providing an ABI-compatible library to intercept simulation data in a transparent way and to facilitate integration into existing simulation codes and tools.

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seminaire passé

[SEMINAR] January 2013 – Gestion des IO parallèle en modélisation du climat – la bibliothèque XIOS 🧑‍🏫 Yann MEURDESOIF

🧑‍🏫 Yann Meurdesoif, Researcher at the Laboratoire des Sciences du Climat et l’Environnement (LSCE)
🌎 January 2013

Abstract:

XIOS est un nouvel outil développé à l’IPSL (Institut Pierre Simon Laplace) destiné à gérer efficacement les sorties fichiers des modèles de simulations climatiques. Il vise deux principaux objectifs :

  • Souplesse d’utilisation, grâce à une description externe des I/O sous forme d’un fichier XML hiérarchisé et d’une API fortran permettant de compléter ces informations à partir des codes.
  • Performance : des cœurs de calculs sont exclusivement dédiés à la gestion des écritures via une technologie client/serveur, les données étant transmises des clients (code de calcul) vers les serveurs (cœurs I/O) par des communications MPI asynchrones non bloquantes. L’écriture des fichiers se fait alors en tâche de fond, en même temps que les calculs. Lors des phases d’écriture, XIOS exploite également le parallélisme du système de fichier via l’utilisation des bibliothèques netcdf4/hdf5 parallèle, permettant à plusieurs processus d’écrire simultanément dans un même fichier, et agrégeant ainsi la bande passante I/O vers les supports matériels.

Slides:

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Non classé seminaire passé

[SEMINAR] December 2012 – Software optimization for petaflops/s scale Quantum Monte Carlo simulations 🧑‍🏫 by Anthony SCEMAMA

🧑‍🏫 Anthony Scemama, Research Engineer at the Laboratoire de Chimie et de Physique Quantiques of IRSAMC
🌎 December 2012

Quantum chemistry is known to be one of the grand challenges of modern science since many fundamental and applied fields are concerned (drug design, micro-electronics, nanosciences,…). To investigate all these fascinating problems is a tremendous task since highly accurate solutions of the fundamental underlying Schrödinger equation for a (very) large number of electrons need to be determined. The use of Quantum Monte Carlo methods is an emerging alternative approach to usual methods since they can take advantage of massively parallel architectures. In this talk the QMC=Chem program we develop in Toulouse will be presented, as well as the different strategies we used to reach the petaflops/s scale.

Slides :