Windows Server 2012
, while it's technically possible to team network cards of different speeds into a single NIC team, it's not a good idea for several reasons.
- It's not supported by Microsoft.
- The native NIC teaming solution algorithms don't take the speed of the NIC into consideration when balancing traffic and instead just balance traffic evenly between adapters. This means if a single team had a 1 Gbps adapter and a 10 Gbps adapter, each adapter would get half of the traffic, which isn't optimal.
- On a similar point to number 2, should adapters of a higher bandwidth fail, then performance would drop as the lower bandwidth adapters are used, affecting user experience.