Microsoft has finally officially recommended a workaround that some of us have been using for some time to keep the SQL dashboards in a usable state.
Dashboards may work slowly if used rarely
Issue: When used rarely or after a long break, the dashboards may work rather slowly due to large amounts of the collected data to be processed; especially, it is related to large environments (2000+ objects).
Resolution: Below is a “warming up” script, which may be used to create an SQL job to run on some schedule. Before scheduling it as an SQL job, please test how long these queries will be executing (if you will schedule it to run too often or execution time is too long, that may kill the performance). If you have dashboards with thousands of objects to load, then time to load the content will be 10+ seconds anyway. It was tested with 600 000 objects, and the dashboard loading time was 1-2 minutes.
It is also worth noting that the following versions of SQL Server Management Pack are considered as deprecated and suspended: