Tracking on GPU at LHCb’s fully software trigger

The LHCb experiment will use a fully software-based trigger to collect data from 2022 on, at an event rate of 30 MHz. During the first stage of the High-Level Trigger (HLT1), a partial track reconstruction, using efficient parallelisation techniques on GPU cards, is performed. This stage will reduce the event rate by around a factor 30. Reconstructing tracks at 30 MHz represents a challenge which needs to be faced with very performant tracking algorithms. These proceedings focus on reconstruction and performance aspects of HLT1, giving particular attention to the algorithms reconstructing particles traversing the whole LHCb detector.