There are no breaks in event receiver configuration. So it depends on your system performance and on your settings of event receivers.
That what sharepoint documentation says about it:
Synchronous event receivers are called in sequential order based on the sequence number specified during event binding. This applies to both Before and After synchronous events.
Asynchronous After event receiver threads are initiated in sequential order based on the sequence number. However, there is no guarantee that they will finish in that same order.
An asynchronous After event can start at any time after its associated user action is performed. It may start before, at the same time as, or after the Web request is completed.
After a user initiates an action in the SharePoint user interface, and before SharePoint Foundation executes the user action, the synchronous Before events are raised. If there are multiple synchronous Before events, they are raised in the order specified by their sequence number.
Similarly, synchronous After events are raised after SharePoint Foundation executes the user action. These, too, are raised in the order specified by sequence number. As you can see, all synchronous events are processed in the same thread as that in which the user action occurs.
Asynchronous After events, however, are processed on secondary threads.