I have a bunch of computer with onboard Mellanox ConnectX-2 QDR Infiniband 40Gbps Controllers. They have QSFP connectors.
I have a switch with 24 4x CX4 DDR connectors.
If I buy QSFP to CX4 cables, will the QDR controllers on the computers be able to downscale to DDR, and be able to communicate with (through) the switch?