Does Serializable hamper performance?
<p>I recently changed the Session State to use SQL server and then realized not all my entities were serializable.</p>

<p>Now trying to find out which entities are being put in session throughout the code seems to be a big pain, so I was thinking why not make all of them serializable? </p>

<p>Will this have any performance hit? Why are classes not marked as Serializable by default?</p>
