I am sorry for the delayed reply!
There are some performance improvements in the Beta release of the controls which should not be available for download. You will be able to find it as a trial download as well. Could you please download it and check if you see any performance improvements. In the newer version the DragDrop registers for less mouse events.
Generally a the performance of the DragDrop will be affected by two things:
- The depth of the visual tree - since a lot of routed events are used the deeper the visual tree, the longer it will take for them to travel. Also when searching for a drop target the visual tree is searched for elements under the current mouse position, deeper visual hierarchy will degrade the performance.
- The number of drag sources. The DragDrop needs to sign up for mouse events on all drag sources so that it will know when they ar clicked and dragged. If there are many drag sources, this may also degrade the performance.
You say that
"I am just hovering the mouse over draggable elements"
Do you mean that you see this cpu usage without dragging at all? If this is so, can you check how it works with the beta?
From your question it seems that you see performance issues in a simple scenario. Could you possibly send us the project that you use to test this?
You can mail it to miroslav.paskov [at] telerik [dot] com if you cannot open a support ticket.
the Telerik team