AUTHOR=Bocci A. , Innocente V. , Kortelainen M. , Pantaleo F. , Rovere M. TITLE=Heterogeneous Reconstruction of Tracks and Primary Vertices With the CMS Pixel Tracker JOURNAL=Frontiers in Big Data VOLUME=3 YEAR=2020 URL=https://www.frontiersin.org/journals/big-data/articles/10.3389/fdata.2020.601728 DOI=10.3389/fdata.2020.601728 ISSN=2624-909X ABSTRACT=

The High-Luminosity upgrade of the Large Hadron Collider (LHC) will see the accelerator reach an instantaneous luminosity of 7 × 1034 cm−2 s−1 with an average pileup of 200 proton-proton collisions. These conditions will pose an unprecedented challenge to the online and offline reconstruction software developed by the experiments. The computational complexity will exceed by far the expected increase in processing power for conventional CPUs, demanding an alternative approach. Industry and High-Performance Computing (HPC) centers are successfully using heterogeneous computing platforms to achieve higher throughput and better energy efficiency by matching each job to the most appropriate architecture. In this paper we will describe the results of a heterogeneous implementation of pixel tracks and vertices reconstruction chain on Graphics Processing Units (GPUs). The framework has been designed and developed to be integrated in the CMS reconstruction software, CMSSW. The speed up achieved by leveraging GPUs allows for more complex algorithms to be executed, obtaining better physics output and a higher throughput.