A first look at 100 Gbps LAN technologies, with an emphasis on future DAQ applications

The LHCb experiment is preparing a major upgrade, during long shutdown 2 in 2018, of both the detector and the data acquisition system. A system capable of transporting up to 50 Tbps of data will be required. This can only be achieved in a manageable way using 100 Gbps links. Such links recently became available also in the servers, while they have been available between switches already for a while. We present first measurements with such links using standard benchmarks and using a prototype event-building application. We analyse the CPU load effects by using Remote DMA technologies, and we also show comparison with previous tests on 40G equipment.