MULTINODE COMPUTER SYSTEM WITH CACHE FOR COMBINED TAGS

Local memory on a node in a multinode, multiprocessor computer system with distributed shared memory and a remote cache is efficiently updated through the use of a combined tag stored in a tag cache. In response to a local processor request for access to local memory that does not contain a current copy of the data requested, a combined tag is formed from a memory tag and a remote cache tag. The combined tag allows the node to operate in accordance with the network protocol such as the Scalable Coherent Interface (SCI) while the memory is being updated, acting as memory in response to requests from other nodes to the memory and as a cache in response to requests from other nodes to the remote cache. In this way the memory is updated quickly and the remote cache is not required to store data that is better stored in the local memory.