I've read that implementing Externalizable provides faster
performance that Serializable, at least according to:

http://www.onjava.com/pub/a/onjava/excerpt/JavaRMI_10/index.html?page=5

is that when I write my marshalling methods, I do not have
to marshall the superclasses of my object (which Serializing
does automatically). Is that right?

However, suppose I have a simple class (whose superclass
is Object) and contains only an int, a String, and a byte array.
Since there is no superclass, implementing Externalizable
or Serializable should not make much of a difference in
terms of performance, no? Indeed, my cursory implementation
both ways shows little difference at all (and any differences
are within the boundaries of experimental error).