During Run 3, the ALICE experiment has enhanced its two-phase data processing and reconstruction chain by integrating GPUs, a leap forward in utilizing high-performance computing at the LHC. The initial ’synchronous’ phase engages GPUs to reconstruct and compress data from the TPC detector. Subsequently, the ’asynchronous’ phase partially frees GPU resources, allowing further offloading of additional reconstruction tasks to enhance the reconstruction efficiency. Notably, the Inner Tracking System (ITS) 5 tracking has been ported as an independent module for two major GPU platforms. This work will detail the integration of ITS GPU tracking within the existing framework, aiming to develop a unified GPU-based reconstruction pipeline that minimizes host-device memory transfer latency and coordinating various simultaneous processing stages. Performance metrics of the integrated system will be discussed, highlighting the technical strategies and outcomes of this implementation.
Concas et al. (Wed,) studied this question.