Purpose of wired adapter?

Solution
They are useful for older boards that only support 10/100, and less so for newer systems, however there are some very specific applications which benefit from having additional network ports where you need additional bandwidth available, more than a single gigabit connection can provide, most of the data being accessed would have to live in RAM or Flash memory, if you had a system running several of the PCI-E flash memory cards that needed to get accessed remotely by several machines simultaneously, that could make use of multiple gigabit connections.


For most people a single connection is fine, but there is a reason for having multiple ones.
They are useful for older boards that only support 10/100, and less so for newer systems, however there are some very specific applications which benefit from having additional network ports where you need additional bandwidth available, more than a single gigabit connection can provide, most of the data being accessed would have to live in RAM or Flash memory, if you had a system running several of the PCI-E flash memory cards that needed to get accessed remotely by several machines simultaneously, that could make use of multiple gigabit connections.


For most people a single connection is fine, but there is a reason for having multiple ones.
 
Solution