Poor performance rendering saved report output in Business Insight

Unexpected poor performance

A saved report output is used in a Business Insight Dashboard.
User is expecting the saved output to be rendered in the Dashboard thereby improving performance of rendering the dashboard. However, the Dashboard is taking a long time to render the report and it appears that the report is executing instead of retrieving the report output.

The Dashboard contains report parts rather than a full report.

Diagnosing the problem
Check the following to see if the Dashboard contains report parts.
If the Widget Actions > Versions menu is disabled, this indicates that the widget is using report parts and not the full report.

According to Business Insight User Guide 10.1.0 - Understanding IBM Cognos Business Insight > Upgrading IBM Cognos 8 Go! Dashboards > Upgrade limitations:

In Go! Dashboard, enabling the "enable enhanced user features in saved output versions" option allows report parts to be rendered as saved output. Rendering saved output for report parts is not supported in Business Insight. Instead, Business Insight renders live reports. As a result, a Go! Dashboard report might look different when opened in Business Insight.
To use saved report output, add the full report in the dashboard rather than report parts.