At first we used an Intel DC P3700 NVMe adapter for the target device. We could easily get 2,500 MB/s of random read performance out of it. However, we soon reached the peak performance of the adapter in the InfiniBand tests.
So we switched to using a 200 GB RAM disk instead for the target device. We are only interested in comparing the transport protocols here, not NVMe performance. So the RAM disk is perfect.