We have Mellanox Infiniband FDR cards and cables supporting it. We want to reduce the speed of the adapters from 56 Gbps to 40 Gbps. We tried using ibportstate <base lid> <port id> of the node. However, it does not help. Please let me know the exact sequence of commands to do so.
Card :
Mellanox Tech. MT27500 Family [ConnectX-3]
Switch : Mellanox 6536 Switch