The amount of memory resources available for database zones depends on the type of SuperCluster you have. Each CMIOU has 16 DIMM slots, for:
A total of 1 TB (64 GB DIMMs) of total available memory in Oracle SuperCluster M8
A total of 512 GB (32 GB DIMMs) of total available memory in Oracle SuperCluster M7
The amount of memory resources available for database zones also depends on the amount of memory resources that you have assigned to the Database Domain, and then how you want to divide those memory resources up for the database zones within that Database Domain.
For example, assume you have Oracle SuperCluster M7, and you have a Database Domain that has one CMIOU associated with it. By default, 512 GB of memory would be available to that Database Domain. You could therefore have four equal-sized database zones within that Database Domain, where each database zone has 100 GB of memory assigned to it, for a total of 400 GB of memory for all database zones. The remaining 112 GB of memory in this Database Domain could then be saved for future database zones that you might want to create on this Database Domain.