A 32 terabit/s data acquisition from mostly COTS components

The LHCb data acquisition after 2019 will need to perform event-building at an aggregated band-width of 32 Tbit/s. Apart from the technological challenges described in various papers also at this conference, the key challenge is to come up with an architecture which minimises the cost, while providing a system which can be maintained by a small team for a long time and which scales well. In this paper we present the analyses we have been doing to minimise the cost, the R&D topics we derived from that and how we combined all this into a coherent proposal which allows us to come up with a system which not only today fits the budgetary constraints of LHCb, but also will allow profiting from any main-stream technological development. We achieve this by aligning our system needs as much as possible to data-centre mass-market commercial of the shelf (COTS) products; by minimising the number of optical interconnects and by optimising the physical layout of the system. This system requires only one piece of custom-made hardware, and even this could, for a smaller setup be replaced by a commercially available item. We believe that the reasoning behind this design can be beneficial to any large, high-rate data acquisition system.