MickU,   It appears all of the nics support RDMA, as seen on the table here. Also,  the page here clarifies that both iWarp and RoCE are supported, and the differences of both.Now as far as the RDMA version, I am not certain on that, but can research it for you.   Let me know if this helps.    
Do these NIC's support RDMA and if yes then RoCEv2 or iWARP? Multiple R740 server have the follow cards: Intel Ethernet 10G 4P X550/1350 rNDCIntel Gigabit 4p X550/1350 rNDC Intel(R) Ethernet 10G 4P X710/I350 rNDCIntel(R) Gigabit 4P X710/I350 rNDC Which type of RDMA is supported?
PowerEdge R740 - RDMA (RoCEv2 or iWARP) support on NICs