The IBM System z Integrated Information Processor (zIIP) is a specialty engine designed to offload eligible workload from a GCP (general central processor) to a zIIP.

Offloading workload to a zIIP helps optimize resource capacities and free up part of the GCPs for new workloads, while lowering the mainframe TCO (total cost of ownership). GCPs are more expensive than zIIPs, both in their direct cost and in their impact on software license costs. Also, GCPs may run throttled, whereas zIIPs always run at full speed.

For detailed information on the zIIP, refer to the appropriate IBM literature.

The simple graphic below illustrates the purpose of the zIIP: