PowerServer Performance Tuning Guide
Tuning: Heavy Client

Redesign the navigation strategy to present a lighter-weight Client user interface. Specifically, you would want to focus on reduce the number of DataWindows and DropDownDatawindows in a particular window or tab page. In many situations, the DataWindows in a Window can be spread out across multiple Windows or tabs, thereby reducing the "weight" of the Window. It may be possible to rework your DropDownDataWindows as DropDownListBoxes. By thinning out the UI, it will not only make the Window run faster but your users will not be overwhelmed by so much data.