Definition
Processor-based licensing ties the cost of IBM i and most IBM i software to a processor group, commonly shortened to P-group, such as P05, P10, P20, or higher. Each P-group reflects a relative performance tier rather than a raw core count, and IBM assigns machines to a P-group based on their processor characteristics. The higher the tier, the higher the license cost for the base OS and for much of the third-party software layered on top of it.
Because P-groups are assigned per machine, moving from one Power generation to another almost always means revisiting the licensing conversation. Power 10 and Power 11 systems have their own P-group mappings that do not simply carry over from Power 9, so a hardware refresh typically triggers a re-issue or repurchase of entitlements for IBM i itself and for any ISV software licensed the same way.