Performance of the CMS Event Builder

Jean‐Marc André ,L Masetti ,R K Mommsen ,Christian Deldicque ,Philipp Brummer ,Nicolas Doualot ,Jonathan Fulcher ,Benjamin Gordon Craigs ,R Jimenez-Estupiñán ,Olivier Chaze ,M Janulis ,G Gómez-Ceballos ,M Pieri ,L Orsini ,H Sakulin ,V O’dell ,Z Demiragli ,F Meijers ,Maciej Gładki ,E Meschi ,Cristian I Contescu ,A Rácz ,C Paus ,M Dobson ,U Behrens ,S Morovic ,T Reis ,D Gigi ,A Holzner ,C Schwick ,Georgiana-Lavinia Darlea ,S Erhan ,F Glege ,S Cittolin ,Petia Petrova ,Dainius Šimelevičius ,J Hegeman ,J G Branson ,Petr Žejdl

doi:10.1088/1742-6596/898/3/032020

Abstract

The data acquisition system (DAQ) of the CMS experiment at the CERN Large Hadron Collider assembles events at a rate of 100 kHz, transporting event data at an aggregate throughput of to the high-level trigger farm. The DAQ architecture is based on state-of-the-art network technologies for the event building. For the data concentration, 10/40 Gbit/s Ethernet technologies are used together with a reduced TCP/IP protocol implemented in FPGA for a reliable transport between custom electronics and commercial computing hardware. A 56 Gbit/s Infiniband FDR Clos network has been chosen for the event builder. This paper presents the implementation and performance of the event-building system.

Highlights

The Compact Muon Solenoid (CMS) experiment at CERN is one of the two general purpose experiments located at the Large Hadron Collider (LHC)
The main motivation for the upgrade is the aging of the existing hardware, and the need to accommodate sub-detectors with upgraded off-detector electronics that exceed the original specification of the data acquisition system (DAQ) system
The event building is done in two steps: First, the data concentrator aggregates data from 1-18 Front-End Drivers (FEDs) into a super-fragment, and second, the event builder assembles the superfragments into complete events

Summary

Introduction

The Compact Muon Solenoid (CMS) experiment at CERN is one of the two general purpose experiments located at the LHC. The event building is done in two steps: First, the data concentrator aggregates data from 1-18 FEDs into a super-fragment, and second, the event builder assembles the superfragments into complete events.

Results

Conclusion