[geerlingguy]

Datacenters are up to 400 Gbps and beyond (many places are adopting 1+ Tbps on core switching).

However, individual servers may still operate at 10, 25, or 40 Gbps to save cost on the thousands of NICs in a row of racks. Alternatively, servers with multiple 100G connections split that bandwidth allocation up among dozens of VMs so each one gets 1 or 10G.