What are the different ways to improve the performance of the gantt with a large set of tasks?

a) GanttControl.WorkTimeSchedule property

Note that by default the GanttControl uses a "5 days a week, 8 hours a day" work-time schedule to calculate the duration of a task. But, it's possible that in your gantt application, you don't care for specific working-times. You might simply want to follow a 24 X 7 schedule where a task with 24 hour effort would have a duration of 1 day (in a 8 X 5 schedule the duration would be 3 days or more if it spans across weekends).

To set a 24 X 7 schedule which in turn would improve load time performance, do this:

this.ganttControl.WorkTimeSchedule = null;

b) Disable Time Validations while building the Model

The gantt model does a lot of validations when the activity's times are set. But, validating the times might be unnecessary, if you know for a fact that the persisted times are proper (the start and end times don't fall under non-working times, etc.). To turn off validation for such scenarios, do this before setting the ItemsSource:

this.ganttControl.EnforceDependencyConstraints = false;

this.ganttControl.ValidateDependencySetting = false;

this.ganttControl.ItemsSource = this.GetDataSource();

... and turn it back on like this after setting the ItemsSource:

// Good practice to enclose multiple settings within the DelayUpdates block to improve performance

using (new DelayUpdates())

{

this.ganttControl.EnforceDependencyConstraints = true;

this.ganttControl.ValidateDependencySetting = true;

}