Michele Michelotto (INFN + Hepix)
The SPEC INT benchmark has been used as a performance reference for computing in the HEP community for the past 20 years. The SPEC CPU INT 2000 (SI2K) unit of performance has been used by the major HEP experiments both in the Computing Technical Design Report for the LHC experiments and in the evaluation of the Computing Centres. At recent HEPiX meetings several HEP sites have reported disagreements between actual machine performances and the scores reported by SPEC. Our group performed a detailed comparison of Simulation and Reconstruction code performances from the four LHC experiments in order to find a successor to the SI2K benchmark. We analyzed the new benchmarks from SPEC CPU 2006 suite, both integer and floating point, in order to find the best agreement with the HEP code behaviour, with particular attention paid to reproducing the actual environment of HEP farm i,e., each job running independently on each core, and matching compiler, optimization, percentage of integer and floating point operations, and ease of use.
Alessandro De Salvo (INFN + Atlas) Alex Iribarren (CERN) Andreas Hirstius (CERN) Franco Brasolin (INFN + Atlas) Gabriele Benelli (CERN + CMS) Helge Meinhard (CERN + Hepix) Hubert Degaudenzi (CERN + LhcB) Ian Gable (Victoria Univ. + Hepix) Manfred Alef (GridKa + Hepix) Martin Bly (RAL + Hepix) Michele Michelotto (INFN + Hepix) Peter Hristov (CERN + Alice) Peter Wegner (DESY)