In Eye Candy 7, there is an option that allows an effect to be generated on its own layer when possible.
To find this feature, locate the Eye Candy 7 preferences menu as shown below.
The options are at the bottom of the Preferences window.
Keep in mind that this does not work with all effects. If it is not an option for the effect, it will revert to the old functionality and duplicate the layer with the effect applied.
Effect on same layer
In this shadow example, Eye Candy duplicates the layer and adds the effect to it. There is no way to move or otherwise adjust the effect after it is rendered.
Effect on its own layer
Both the original layer and the effect are separated. This provides you with a lot more control and probably some extra time.