The Dashboard Preferences dialog box is displayed.

• Sample Interval — The number of seconds between metric samples. The default is 20 seconds. The minimum accepted value is 10 seconds.
• Maximum Samples — The maximum number of samples stored in the browser's memory. The default is 100. (Note that maximum samples also applies to custom time range charts. If you want to display collected metrics in a custom time range chart for a period that exceeds 24 hours, you need to increase maximum samples to a value greater than 288, assuming the default sampling interval of 20 seconds.)
• Default Chart Time Range — The default span of time shown in time series charts. The default is 5 minutes. (Note that you can change the span of time shown in a chart by zooming in. See Zoom in and out of metrics data in a chart.)
• Chart Zoom Increment — The default increment, as percentage of the horizontal axis of the chart, by which the chart can be zoomed in or out; that is, by a single click of the Zoom button. The default is 20 per cent. For example, if the default chart time range is five minutes, clicking Zoom once redisplays the chart to show a 4 minute time span.
• Default Chart Type — The default type used when you create a new chart. The initial default chart type is Line Plot, but you can change it to Bar Chart, Scatter Plot, Vertical Linear Gauge, Horizontal Linear Gauge, or Radial Gauge. Changing the default chart type does not affect existing charts in the Monitoring Dashboard. For more information, see Choose the chart type.
• Show Series Overview — The series overview, which is available for all time-series charts, indicates the portion of metrics data currently visible in the chart in relation to the whole set of data that has been collected for the corresponding metrics for the represented period of time. This setting determines when the overview is displayed: Never, only when the chart is selected, or always. Choosing Never may help reduce overall visual clutter, but choosing When Selected or Always enables you to take advantage of this item as a convenient control for panning and zooming data. Additionally, on slower systems, or when there many charts in a view, selecting Never or When Selected may help improve performance.

Note: The maximum samples setting, together with the sample interval, give you control over how much data is stored in the browser, thereby providing indirect control over how much data is graphed. Setting the sample interval low and the maximum samples high increases the total amount of memory used by the browser and decreases the rate at which the browser reaches that total. The Monitoring Dashboard manages data efficiently by storing metric samples only once, even if the metric is displayed in multiple charts and views. Note also that in Internet Explorer, the amount of data graphed at any given time can affect performance.