It depends on the amount of virtual memory allocated to the stack.

http://www.odi.ch/weblog/posting.php?posting=411

You can tune this with the -Xss VM parameter or with the [Thread(ThreadGroup, Runnable, String, long)](http://download.oracle.com/javase/6/docs/api/java/lang/Thread.html#Thread%28java.lang.ThreadGroup,%20java.lang.Runnable,%20java.lang.String,%20long%29) constructor.