A multiprocessor system and method includes a processing sub-system including a plurality of processors and a processor memory system. A network is operable to couple the processing sub-system to an input/output (I/O) sub-system. The I/O sub-system includes a plurality of I/O interfaces each operable to couple a peripheral device to the multiprocessor system. The I/O interfaces each include a local memory operable to store a copy of data from the processor memory system for use by a corresponding peripheral device and to delete the copy at a first time event. A directory for the processor is operable to identify the data as owned upon providing the copy to the I/O sub-system and to identify the data as unowned at a second time event.