As a best practice, when creating graphs for dashboards, we recommend using plots to take advantage of improved speed and processing enhancements. Furthermore, plots enable you to highlight the activity of specific metrics while keeping the graph tidy.
Adding a Plot
Click the menu button to the right of a graph and choose "Edit Graph":
Click the "Add Plot" button on the "Edit Graph" dialog. The "Graph Plot" child dialog will then be displayed.
Specify a function and filter (a DataSet search query) along with a label and color. Click "Save", and your plot will be displayed on the "Edit Graph" page: