VELO: A Novel Communication Engine for Ultra-Low Latency Message Transfers

This paper presents a novel stateless, virtualized communication engine for sub-microsecond latency. Using a field-programmable-gate-array (FPGA) based prototype we show a latency of 970 ns between two machines with our virtualized engine for low overhead (VELO). The FPGA device is directly connected to the CPUs by a hypertransport link. The described hardware architecture is optimized for small messages and avoids the overhead typically found with direct-memory access (DMA) controlled transfers. The stateless approach allows to use the hardware unit directly from many threads and processes simultaneously. It provides a secure user level communication with an extremely optimized start-up phase. Micro benchmarks results are reported both based on proprietary API and OpenMPI basis.