Explanation
Resource provider resource consumption
The resource consumption by the Event Hubs resource provider is constant, and independent of the number or sizes of clusters created by users. The following table shows the core utilization by the Event Hubs resource provider on Azure Stack Hub, and the approximate resource consumption by other resources. The Event Hubs resource provider uses a D2_V2 VM type for its deployment.

Note: Cluster resource consumption
Your users will need to create Event Hubs clusters with CUs that meet their business requirements. To inform your decision on quota configuration, the following table shows:
The total cores used by a 1 CU Event Hubs cluster.
The approximate capacity required for consumption of other resources, including VM storage, memory, and storage accounts.

Reference: https://learn.microsoft.com/en-us/azure-stack/operator/event-hubs-rp-capacity-planning