Write Bytes Non-Paging/sec is the rate at which bytes are written by the Redirector in response to normal file outputs by ...

Write Bytes Non-Paging/sec is the rate at which bytes are written by the Redirector in response to normal file outputs by an application when they are redirected to another computer.  In addition to file requests, this count includes other methods of writing across the network, such as Named Pipes and Transactions.  This counter does not count network protocol information, just application data.