When using minute or second charts, the Insider Bars indicators have the option to save calculated data with the workspace. This reduces load times significantly once data has been loaded, since far less data must be read, sorted and processed.
For this option to work properly, the workspace must be saved each time you close the platform. If not, all the newly collected data is not saved and must be re-downloaded.
Note: Blog posts like this one offer basic information. For more details, see online help.