First experiences with a parallel architecture testbed in the LHCb trigger system

In this note we will discuss the application of new technologies, such as GPU cards, in the current LHCb trigger system. During Run2, a node equipped with a GPU has been inserted in the LHCb online monitoring system. During normal data taking, real events have been sent to the node and processed by GPU-based and CPU-based tracking algorithms. This gave us the unique opportunity to test the new hardware and the new algorithms in the real-time environment of the experiment. In the following sections, we will describe the algorithm developed for parallel architectures, the setup of the testbed and the results compared to the LHCb official reconstruction.In view of Run3 (2020) the LHCb experiment is planning a major upgrade to fully readout events at 40 MHz collision rate. This in order to highly increase the statistic of the collected samples and go further in precision beyond Run2. An unprecedented amount of data will be produced, which will be fully reconstructed real-time to perform fast selection and categorization of interesting events. The collaboration has decided to go for a fully software trigger which will have a total time budget of 13 ms to take a decision. This calls for faster hardware and software. In this talk we will present our efforts on the application of new technologies, such as GPU cards, for the future LHCb trigger system. During Run2 a node equipped with a GPU has been inserted in the LHCb online monitoring system; during normal data taking, a subset of real events is sent to the node and processed in parallel by GPU-based and CPU-based track reconstruction algorithms. This gives us the unique opportunity to test the new hardware and the new algorithms in a realistic environment. We will present the setup of the testbed, the algorithms developed for parallel architectures and discuss the performance compared to the current LHCb track reconstruction algorithms