Report Server DB

[DLGross]

Can the Report Server Catalog DB be installed on a SQL Server instance that is being used for SharePoint or should it be put into a separate instance?

[Petebro]

Generally speaking the Power BI Report Server does not care what else is hosted on the SQL database instance that holds it's catalog. That said if the SQL instance is overloaded or running near capacity it could lead to slower performance than if the catalog were on an isolated SQL instance. 

The recommendation for Power BI Report Server is similiar any application backed by a database; make sure the isntance where the database is hosted is available and responsive.