Keycloak performance on Kubernates

I run load tests for the latest keycloak version: 11.0.2 in Azure Kubernetes. I am using this official image The test just calls authorize endpoint n times per second. Here is an example:
-d “client_id=admin-cli”
-d “username=admin”
-d “password=password”
-d “grant_type=password”

Node count: 1
VM: DS4 v2 (8 cores)
Pods: 3
The database contains only default data (1 user, 1 realm)

60 Logins per second hits CPU of VM to 100 % and the average response time became 60 seconds.
Is it misconfiguration of keycloak on Kubernetes or expected behavior?

Are you using H2 integrated database or external SQL?