virtualbox.org

If possible, create emulation for a 2.5 gigabit ethernet adapter.

Thanks

Interesting request. As I have read, the actual bandwidth of the Virtualbox network into the VM is a substantial fraction of the bandwidth of the host adapter, barring CPU load and bugs.

In other words, Virtualbox's PCnet-fast 100Mbps adapter, for example, would feed closer to the Virtualbox Intel 1Gbps adapter speeds if the host really had a 1Gbps physical adapter. The "speed" in the adapter's name wouldn't limit the actual bandwidth.

Do you have a reason to require a 2.5Gbps adapter? It wouldn't help unless you had a 2.5Gbps physical adapter in the host.

VirtualBox does not do specific Ethernet speeds. It provides an Ethernet compliant interface. The speed is a function of the underlying connection.