Most high performance computing clusters are nowadays composed of large multicore machines that expose Non-Uniform Memory Access (NUMA), and they are interconnected using modern communication paradigms, such as Remote Direct Memory Access (RDMA). In this work we perform a study outlining the performance impact of these two technologies, NUMA and RDMA, when combined. Findings show that system's software architecture should be designed for NUMA and RDMA; otherwise major performance penalties occur.