152187 20251017144555.0 doi 10.1140/epjst/e2012-01636-9 sideral 78887 ART-2012-78887 eng Baity-Jesi, M. Reconfigurable computing for Monte Carlo simulations: Results and prospects of the Janus project 2012 Access copy available to the general public Unrestricted We describe Janus, a massively parallel FPGA-based computer optimized for the simulation of spin glasses, theoretical models for the behavior of glassy materials. FPGAs (as compared to GPUs or many-core processors) provide a complementary approach to massively parallel computing. In particular, our model problem is formulated in terms of binary variables, and floating-point operations can be (almost) completely avoided. The FPGA architecture allows us to run many independent threads with almost no latencies in memory access, thus updating up to 1024 spins per cycle. We describe Janus in detail and we summarize the physics results obtained in four years of operation of this machine; we discuss two types of physics applications: long simulations on very large systems (which try to mimic and provide understanding about the experimental non-equilibrium dynamics), and low-temperature equilibrium simulations using an artificial parallel tempering dynamics. The time scale of our non-equilibrium simulations spans eleven orders of magnitude (from picoseconds to a tenth of a second). On the other hand, our equilibrium simulations are unprecedented both because of the low temperatures reached and for the large systems that we have brought to equilibrium. A finite-time scaling ansatz emerges from the detailed comparison of the two sets of simulations. Janus has made it possible to perform spin-glass simulations that would take several decades on more conventional architectures. The paper ends with an assessment of the potential of possible future versions of the Janus architecture, based on state-of-the-art technology. info:eu-repo/grantAgreement/EC/FP7/247328/EU/Critical Phenomena in Random Systems/CRIPHERASY info:eu-repo/grantAgreement/ES/MEC/FIS2006-08533 info:eu-repo/grantAgreement/ES/MEC/FPA2004-02602 info:eu-repo/grantAgreement/ES/MICINN/FIS2007-60977 info:eu-repo/grantAgreement/ES/MICINN/FIS2009-12648 info:eu-repo/grantAgreement/ES/MICINN/FIS2010-16587 info:eu-repo/grantAgreement/ES/MICINN/TEC2010-19207 info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 1.796 2012 PHYSICS, MULTIDISCIPLINARY 23 / 83 = 0.277 2012 Q2 T1 info:eu-repo/semantics/article info:eu-repo/semantics/submittedVersion Baños, R.A. Universidad de Zaragoza (orcid)0000-0002-5060-7658 Cruz, A. Universidad de Zaragoza (orcid)0000-0002-7934-7271 Fernandez, L.A. Gil-Narvion, J. (orcid)0000-0003-2903-3044 Gordillo-Guerrero, A. Guidetti, M. Iñiguez, D. (orcid)0000-0003-2916-5493 Maiorano, A. Mantovani, F. Marinari, E. Martin-Mayor, V. Monforte-Garcia, J. Universidad de Zaragoza Sudupe, A.M. Navarro, D. Universidad de Zaragoza (orcid)0000-0002-0795-8743 Parisi, G. Pivanti, M. Perez-Gaviro, S. Ricci-Tersenghi, F. Ruiz-Lorenzo, J. Schifano, S.F. Seoane, B. Universidad de Zaragoza (orcid)0000-0002-5967-2827 Tarancon, A. Universidad de Zaragoza (orcid)0000-0003-2772-3762 Tellez, P. Tripiccione, R. Yllanes, D. (orcid)0000-0001-7276-2942 5008 785 Universidad de Zaragoza Dpto. Ingeniería Electrón.Com. Área Tecnología Electrónica 5005 555 Universidad de Zaragoza Dpto. Ing.Quím.Tecnol.Med.Amb. Área Ingeniería Química 2004 405 Universidad de Zaragoza Dpto. Física Teórica Área Física Teórica 210, 1 (2012), 33-51 Eur. phys. j., spec. top. European Physical Journal-Special Topics 1951-6355 408644 http://zaguan.unizar.es/record/152187/files/texto_completo.pdf Preprint 1795744 http://zaguan.unizar.es/record/152187/files/texto_completo.jpg?subformat=icon icon Preprint oai:zaguan.unizar.es:152187 articulos driver 2025-10-17-14:12:53 ARTICLE