@article{9a6e2eda59e34da9ae72cea281d63a5f,
title = "A Comparison of CPU and GPU Implementations for the LHCb Experiment Run 3 Trigger",
abstract = "The Large Hadron Collider beauty (LHCb) experiment at CERN is undergoing an upgrade in preparation for the Run 3 data collection period at the Large Hadron Collider (LHC). As part of this upgrade, the trigger is moving to a full software implementation operating at the LHC bunch crossing rate. We present an evaluation of a CPU-based and a GPU-based implementation of the first stage of the high-level trigger. After a detailed comparison, both options are found to be viable. This document summarizes the performance and implementation details of these options, the outcome of which has led to the choice of the GPU-based implementation as the baseline.",
keywords = "Heterogeneous, High-level trigger, High-throughput, Parallel computing, Real-time, Software",
author = "\{The LHCb collaboration\} and R. Aaij and M. Adinolfi and S. Aiola and S. Akar and J. Albrecht and M. Alexander and S. Amato and Y. Amhis and F. Archilli and M. Bala and G. Bassi and L. Bian and Blago, \{M. P.\} and T. Boettcher and A. Boldyrev and S. Borghi and Rodriguez, \{A. Brea\} and L. Calefice and Gomez, \{M. Calvo\} and P{\'e}rez, \{D. H.C{\'a}mpora\} and A. Cardini and M. Cattaneo and V. Chobanova and G. Ciezarek and Vidal, \{X. Cid\} and Cobbledick, \{J. L.\} and Coelho, \{J. A.B.\} and T. Colombo and A. Contu and B. Couturier and Craik, \{D. C.\} and R. Currie and P. d{\textquoteright}Argent and \{De Cian\}, M. and D. Derkach and F. Dordei and M. Dorigo and L. Dufour and P. Durante and A. Dziurda and A. Dzyuba and S. Easo and S. Esen and Declara, \{P. Fernandez\} and S. Filippov and C. Fitzpatrick and M. Frank and P. Gandini and E. Golobardes and X. Vilasis-Cardona",
note = "Funding Information: We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MEiN and NCN UMO-2018/31/B/ST2/03998 (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and NERSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from ARC and ARDC (Australia); AvH Foundation (Germany); EPLANET, Marie Sk{\l}odowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, IPhU and Labex P2IO, and R{\'e}gion Auvergne-Rh{\^o}ne-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, CAS CCEPP, Fundamental Research Funds for the Central Universities, and Sci. \& Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Leverhulme Trust, the Royal Society and UKRI (United Kingdom). The authors would like to thank the LHCb computing and simulation teams for their support and for producing the simulated LHCb samples used to benchmark the performance of RTA software. Funding Information: We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MEiN and NCN UMO-2018/31/B/ST2/03998 (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and NERSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from ARC and ARDC (Australia); AvH Foundation (Germany); EPLANET, Marie Sk?odowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, IPhU and Labex P2IO, and R?gion Auvergne-Rh?ne-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, CAS CCEPP, Fundamental Research Funds for the Central Universities, and Sci. \& Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Leverhulme Trust, the Royal Society and UKRI (United Kingdom). The authors would like to thank the LHCb computing and simulation teams for their support and for producing the simulated LHCb samples used to benchmark the performance of RTA software. Publisher Copyright: {\textcopyright} 2021, The Author(s).",
year = "2022",
month = dec,
doi = "10.1007/s41781-021-00070-2",
language = "English",
volume = "6",
journal = "Computing and Software for Big Science",
issn = "2510-2044",
publisher = "Springer Nature",
number = "1",
}