How hard does Constrain hit performance?

wirelesstkd

I remember seeing in one of T-Shirt Booth's tutorials that constraining an actor to another actor is a performance hit (I think it was the video about putting a life bar on top of your actor). Does constrain always hit the processor like this? What if I'm constraining an actor's X and Y position to two game attributes? What if I'm constraining multiple actors' X and Y positions to game attributes?

What are the community's best practices for things like this?

Thanks in advance

tatiang

http://forums.gamesalad.com/discussion/53202/lag-time-by-using-the-global-variable-when-moving-blocks