Data access method in the network system and the network system

According to this data access method to be used in a network system, while the tag information is read out from the tag memory, the data is speculatively read out from the memory unit in the self node device. When the read out tag information shows that the speculatively read out data is not found in any of the cache memories, such speculatively read out data is sent to the processor in the self node device. When the read out tag information shows that the speculatively read out data is found in one of the cache memories, the data existing in such cache memory is acquired and sent to the processor in the self node device and the speculatively readout data is abolished.