Introduction
Less data = faster performance (all aggregation calculations will only take into account loaded tasks only)
Less frequent data refresh = faster performance
Limit data you are working on
Use filtering, such as date filtering, if your Box spans a long period of time
Use simple JQL queries (for filters and to set up a box scope)
The more data fields such as columns on Gantt you show while using BigPicture Plugin, the more time it takes for the browser to calculate and render it.
Archive, close, or remove the old boxes
When a box is closed or archived, the data isn’t being refreshed
You can also remove the Boxes you do not need
Data synchronization
Increase the Synchronization time interval
App Configuration > Advanced > Technical info tab
live synchronization - adjust the live sync settings (decrease the live sync interval or turn off)
App Configuration > General > Live sync tab
Statistics collection (Data Center only)
Switch off Fine-grained logging
App Configuration > Advanced > Technical info tab
Switch off the statistics collection
App Configuration > Advanced > Technical info tab
Field mapping
Limit custom field mapping
Jira issues and projects
Disable widgets on the issue view (should improve the loading time of Jira issues)
Keep in mind, each additional plugin installed shares Jira's resources
Archive old Jira projects
Disable the "Save task changes to Jira issue page"
App Configuration > General > Field mapping
Browser
Make sure that your browser does NOT block caching