title: Is it true that comparison is slower than type casting, and boxing is even slower?
body: <p>I heard about that <code>type casting</code> is slow. I had thought <code>comparison</code> is fast, but...</p>
  
  <p>It seems <code>IComparable.CompareTo(object y)</code> has to use the <code>cast</code>, which would make <code>x &gt; y</code> at least as slow as <code>y as MyClass</code> if not slower if there is no <code>IComparable&lt;T&gt;</code> available.</p>
  
  <p>So, am I right to say that:</p>
  
  <p>It is always better to implement <code>IComparable&lt;T&gt;</code> than <code>IComparable</code> because then we don't have to type cast?</p>
  
  <h3>Update</h3>
  
  <p>Is <code>boxing</code> much slower than type casting between 2 reference types?</p>