To access report Settings dialogue window, hover your mouse over button Edit and select option Settings.
Report settings dialogue window allows you to:
Refresh interval on data change parameter serves to set how often will be changes in the source data set checked. When change in source data is detected, report is automatically refreshed. Default value is set to 2 seconds.
Calculations result validity parameter is dedicated to speedup reports re-loading time. However data are being calculated in-memory and some of them are already cached on database subsystem layer, there is quite huge CPU overhead while computing formula.