I created an event receiver inheriting from SPItemEventReceiver for document libraries that moves files to specific folders and changes some metadata columns that I've added to them.
I created a separate application to update numerous files in a smaller period of time I noticed performance issues.
Ofcourse I looked into some good code practices while writing event receivers on msdn, but a question remains:
Do event receivers have a file ammount to be safely handled in a certain ammount of time? Is there a way to tell what is the safest ammount of files to handle "once"?