HPC (CAP) research group invites you to attend the following talk:

Speaker: Federico Carminati (CERN)

ABSTRACT
High Energy Physics code has been known for making poor use of high performance computing architectures. Efforts in optimising HEP code on vector and RISC architectures have yield limited results and recent studies have shown that, on modern architectures, it achieves a performance between 10% and 50% of the peak one. Although several successful attempts have been made to port selected codes on GPUs, no major HEP code suite has a "High Performance" implementation. With LHC undergoing a major upgrade and a number of challenging experiments on the drawing board, HEP cannot any longer neglect the less-than optimal performance of its code and it has to try making the best usage of the hardware. This activity is one of the foci of the SFT group at CERN, which hosts, among others, the Root and Geant 4 projects. The activity of the experiments is shared and coordinated via a Concurrency Forum, where the experience in optimising HEP code is presented and discussed. Another activity is centred on the development of a high-performance prototype for particle transport. Achieving a good concurrency level on the emerging parallel architectures without a complete redesign of the framework can be done only by parallelizing at the event level, or with a much larger effort at the track level. Apart from the shareable data structures, this typically implies a multiplication factor in terms of memory consumption compared to the single threaded version, together with sub-optimal handling of event processing tails. Besides this, the low level instruction pipelining of modern processors cannot be used efficiently to speedup the program. We have implemented a framework that allows scheduling vectors of particles on an arbitrary number of computing resources in a fine grain parallel approach. The talk will review the current optimisation activities within the SFT group with a particular emphasis on the development perspectives towards a simulation framework able to profit best from the recent technology evolution in computing.

BIOGRAPHY

Federico Carminati is senior Programming Physicist at CERN since 1985. He is presently project leader of the "Fast Simulation Prototype (GEANT5) in the Physics Department. From 2001 to 2011 he has been Computing Coordinator of the ALICE experiment at LHC. After getting his Master in Physics at the University of Pavia, Italy in 1981 he worked at Los Alamos and Caltech as particle physicist before being hired by CERN in the Data Handling Division. He has been responsible for the CERN Program Library and the GEANT detector simulation programme, the world-wide standard High Energy Physics code suite in the 80’s and 90’s. From 1994 to 1998 he worked with Nobel Prize winner Prof. Carlo Rubbia at the design of a novel concept of accelerator-driven nuclear power device. In 2013 he got a PhD in Particle Physics at the University of Nantes.

Organizes: Department of Computer Architecture (DAC)