Connecting DGX Spark to Mellanox Infiniband SB7800

IFIK the ConnectX ports on the DGX Spark are configured in Ethernet mode. To connect the Spark to a switch like SB7800 both ends must speak IB. However, there’s no firmware option to switch the ports to IB. We use RoCE for clustering, which simply means sending IB verbs over Ethernet links. And it works fine on Sparks connected back-to-back.