Use the project cache for large cross-site reports
If you report over a large number of site collections, it can take a while to process and render the data. If you switch on the BrightWork Project Cache, you can improve response and rendering time in large reports.
Use CAML filtering
Using CAML filtering can give your reports a boost. Instead of filtering after rendering, as with reporter based filtering, CAML filters the reports before they appear. If you start working with CAML, you can make some great speed increases.
Disable presence information in large lists
Presence is a SharePoint feature that pulls user information when hovering over their name in a list. This can be a handy feature, but can also be a burden when you have many users in a large list. You can disable presence on an individual web application to get a rendering increase. You can also disable presence on a per-column basis by editing a column and deselecting the Show Presence checkbox.
Archive old sites
Older sites getting pulled in by large cross-site reports can impact performance. You can fix this by moving them into their own separate Project Area using the BrightWork Copy Site feature. You can also edit the project's BrightWork Settings and uncheck the Include Project Statement type lists in reports checkbox.