As we know a dashboard displays key performance indicators (KPIs) at a glance. This usually requires connecting to and aggregating data from various data sources into one consolidated view.
A common solution in SP is using multiple “roll-up” web parts on a page, each running some query to retrieve & display required data.
The problem with this solution is that when you locate multiple “roll-up” web parts performing real-time aggregation on a SharePoint page, it significantly impacts the SharePoint page load time and affects the overall WFE servers’ performance.
This causes your great-looking dashboard
to stop from serving its single purpose:
providing at a glance (=quick) view!