Will upgrading from 17.0 to 18.5 or 19.0 increase zIIP utilization and decrease GP CPU usage?
Yes. Prior to 18.0 CA IDMS the throttled the amount of CPU it would offload to the zIIP specialty engines at approximately 33 percent of zIIP eligible. Starting with 18.0 and above ( IDMS 4712, 18.0 PTF RO63129, 18.5 PTF RO63736) IDMS offloaded 100 percent of zIIP eligible CPU to the zIIP engines. It would be expected that the zIIP CPU would increase significantly and the GP CPU would significantly decrease.
CA IDMS - 19.0, zIIP Exploitation https://docops.ca.com/ca-idms/19/en/administrating/administrating-idms-system-operations/z-os-considerations/ziip-exploitation