Is it advisable to have a SharePoint Content Database on a SQL Database Server that is not specific for SharePoint?
We can't speak to your particular scenario, but in general, SharePoint should have a dedicated SQL server.
Use a dedicated server for SQL Server To ensure optimal performance for farm operations, we recommend that you install SQL Server on a dedicated server that does not run other farm roles and does not host databases for other applications. this is for production.
For Dev/ testing you can use the shared sql server. read more here: