macOS keeps internal statistics about all characteristics which could be interesting to monitor performance and features of the NFS client. The collected data can be shown by selecting the item NFS Client > Statistics in the left overview column of the control window. The hierarchical table Client Statistics appears.
The NFS function calls sent by the client to the NFS servers can be found in the lines containing the word Calls. The behavior of RPC communication between client and servers and the reliability of the network connections can be monitored by the lines containing the word RPC. The use of memory buffers (caches) is described by the lines with the word Cache. A cache hit indicates that a costly network communication could be avoided because the requested information was already/still available in memory. A miss indicates the remaining cases, where the cache could not be used for acceleration.
The readings are updated continuously. The counter values represent the number of events recorded since the operating system has been started.