Databricks classic compute bills DBUs and cloud infrastructure separately. Serverless compute includes infrastructure in a higher DBU rate.
Classic clusters can be less expensive at sustained high utilization because the underlying virtual machines are billed directly. Serverless can be less expensive for intermittent workloads because inactive intervals do not keep customer-managed instances running.
A job that runs 90 seconds every 10 minutes can have a different cost profile from a job that runs continuously. Compare DBUs, infrastructure, startup time, idle time, and workload latency over a representative period.
The applicable rate varies by workload, plan, cloud, and region. Databricks documents serverless.