If you really want to squeeze out all the performance of your network card, what you should use is something like DPDK.
If you really want maximum throughput with RDMA, I think the best is to go InfiniBand.
InfiniBand was the way to go 5/10 years ago, when 10G Ethernet was not there.
Nowadays, most of companies that invested in IB years ago are stuck with a dead infrastructure. It costs a lot, there is very little knowledge about the techno, and most support for it is dropping (e.g. glusterfs).
Sad truth is most of these old IB infra are now used for IPoIB ...
Source: been working in HFT firms implementing IB RDMA, then GBEth RDMA, now proprietary NIC RDMA