The processing capacity does not diminish as the number of systems in the complex increase. This is because all requests for global resources are handled by the coupling facility; not by passing a token between each system in the complex before a request is satisfied. The requests are processed by the coupling facility as they are received, therefore the processing capacity is improved.

Response time is improved in a star as each request for a resource that is not in contention can be completed with only two signals, rather than having to pass the RSA-message to each system in the complex.

Also, in a star complex, the central processing unit (CPU) overhead required to process an ENQ or DEQ request is limited to the system on which the request originated, the coupling facility, and the system chosen to be the global contention manager by XES (if one is needed). Therefore, the total processing time consumed across a star complex will be less than that consumed by a ring complex.

Availability and recovery time is improved for the star because the systems that make up the complex are not dependent on each other, as they are in the ring. The complex does not have to alter processing to adjust to topological changes due to a system joining or leaving the complex. When a system joins or leaves the complex, queue manipulation for resource requests are distributed around the complex, rather than having to be repeated for every request on each system. These changes and adjustments are handled by global resource serialization and XES. Your only requirement is to determine which resource owned by a failing system is in contention and reassign it to a new system.