Allen : A high level trigger on GPUs for LHCb

Aaij, Roel; Schwemmer, Rainer; Ustyuzhanin, Andrey; Albrecht, Johannes; Billoir, Pierre; Williams, Mike; Reiss, Florian; Stevens, Holger; Sokoloff, Michael; Vom Bruch, Dorothea; Brea Rodriguez, Alexandre; Casais Vidal, Adrian; Boettcher, Thomas; Gligorov, Vladimir; Fernandez Declara, Placido; Kazeev, Nikita; Quagliani, Renato; Jashal, Brij Kishor; Vilasis-Cardona, Xavier; Pisani, Flavio; Sanchez Mayordomo, Carlos; Craik, Daniel Charles; Martinez Santos, Diego; Rangel, Murilo; Campora Perez, Daniel Hugo

doi:10.1007/s41781-020-00039-7

Article
Report number	arXiv:1912.09161
Title	Allen : A high level trigger on GPUs for LHCb
Related title	Allen: A high level trigger on GPUs for LHCb
Author(s)	Aaij, Roel (Nikhef, Amsterdam) ; Albrecht, Johannes (Tech. U., Dortmund (main)) ; Billoir, Pierre (Paris U., VI-VII) ; Boettcher, Thomas (MIT) ; Brea Rodriguez, Alexandre (U. Santiago de Compostela (main)) ; Vom Bruch, Dorothea (Paris U., VI-VII) ; Campora Perez, Daniel Hugo (NIKHEF, Amsterdam) ; Casais Vidal, Adrian (U. Santiago de Compostela (main)) ; Craik, Daniel Charles (MIT) ; Fernandez Declara, Placido (CERN) ; Gligorov, Vladimir (Paris U., VI-VII) ; Jashal, Brij Kishor (Valencia U., IFIC) ; Kazeev, Nikita (Higher Sch. of Economics, Moscow) ; Martinez Santos, Diego (U. Santiago de Compostela (main)) ; Pisani, Flavio (CERN) ; Quagliani, Renato (Paris U., VI-VII) ; Rangel, Murilo (Rio de Janeiro Federal U.) ; Reiss, Florian (Paris U., VI-VII) ; Sanchez Mayordomo, Carlos (Valencia U., IFIC) ; Schwemmer, Rainer (CERN) ; Sokoloff, Michael (Cincinnati U.) ; Stevens, Holger (Tech. U., Dortmund (main)) ; Ustyuzhanin, Andrey (Yandex Sch. Data Anal., Moscow ; Higher Sch. of Economics, Moscow) ; Vilasis-Cardona, Xavier (U. Barcelona (main) ; Ramon Llull U., Barcelona) ; Williams, Mike (MIT)
Publication	2020-04-30
Imprint	2019-12-18
Number of pages	11
Note	12 pages, 12 figures, submitted to Computing and Software for Big Science
In:	Comput. Softw. Big Sci. 4 (2020) 7
DOI	10.1007/s41781-020-00039-7
Subject category	hep-ex ; Particle Physics - Experiment ; physics.ins-det ; Detectors and Experimental Techniques
Accelerator/Facility, Experiment	CERN LHC ; LHCb
Abstract	We describe a fully GPU-based implementation of the first level trigger for the upgrade of the LHCb detector, due to start data taking in 2021. We demonstrate that our implementation, named Allen, can process the 40 Tbit/s data rate of the upgraded LHCb detector and perform a wide variety of pattern recognition tasks. These include finding the trajectories of charged particles, finding proton-proton collision points, identifying particles as hadrons or muons, and finding the displaced decay vertices of long-lived particles. We further demonstrate that Allen can be implemented in around 500 scientific or consumer GPU cards, that it is not I/O bound, and can be operated at the full LHC collision rate of 30 MHz. Allen is the first complete high-throughput GPU trigger proposed for a HEP experiment.
Copyright/License	preprint: © 2019-2025 CERN (License: CC-BY-4.0) publication: © 2020-2025 The Author(s) (License: CC-BY-4.0)