An Evaluation of 100-Gb/s LAN Networks for the LHCb DAQ Upgrade

The Large Hadron Collider Beauty experiment (LHCb) experiment is preparing a major upgrade resulting in the need for a high-end network for the data acquisition system. Its capacity will grow up to a target speed of 40 Tb/s, aggregated by 500 nodes. This can only be achieved reasonably by using links that are capable of coping with 100-Gb/s line rates. The constantly increasing need for more and more bandwidth has initiated the development of commercial 100-Gb/s networks. There are three candidates on the horizon that need to be considered: Intel Omni-Path, 100-G Ethernet, and EDR InfiniBand. We present test results with such links using both standard benchmarks (e.g., iperf) and a custom benchmark called Data AcQquisition (DAQ) Protocol Independent Performance Evaluator (DAQPIPE). With DAQPIPE, we mainly evaluate the ability to exploit the targeted network for a kind of all-to-all communication pattern. The key benefit of these measurements is that it helps us to tune our benchmark and improves our understanding of the relevant parameters. It will now permit us to prepare and motivate some upcoming tests at scale on existing supercomputers offering the targeted hardware.