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Processor Arrays

The POWERChallenge Array is a collection of two or more POWERChallenge systems, each one of which is a symmetric multiprocessor as described in the preceding topics. Within each "node" of the Array there are multiple CPUs, a system bus, and a single memory. The nodes are connected by a high-speed network, HIPPI or FDDI.

The real-time features discussed in this book apply within one Challenge/Onyx system, whether it stands alone or is a node in an Array system. You can distribute an application across multiple nodes of an Array using the Message-Passing Interface (MPI) standard. However, the MPI standard does not provide for guaranteed message latencies. As a result, you cannot distribute a real-time application across nodes of an Array. You can run multiple, real-time, applications in different nodes of an Array, but you cannot synchronize them at real-time levels of determinacy.


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