A method and apparatus for efficient interrupt event notification for a scalable input/output device in a network system. A network interface unit is operably connected to a plurality of processing entities and associated memory units. At least one status register in the network interface unit contains information relating to a process to be performed by at least one processing entity communicated to the processing entity by an interrupt event notification. Shared memory space comprises a mailbox storage register operable to store an image of the interrupt information stored in the status register of the network interface unit. A processing entity can directly access the process information stored in the mailbox status register thereby reducing system latency associated with reading information in the status register. Updated process status information in the network interface status register may be read by the processing entity on an interleaved basis while executing a process.