title: Does Too many ids hurt performance
body: <p>If I have in the page unnecessary <code>id</code>s on elements, like the <code>HTML Helper</code> does in <code>ASP.Net-MVC</code>.<br>
  Does it reduce the performace of my id selectors? (I have a page with enormous amout of elements)</p>
  
  <p><strong>Example:</strong></p>
  
  <pre><code>// First DOM   
  &lt;HTML&gt;
  ...
      &lt;input type="text" value="first" id="useless" /&gt;
      &lt;input type="text" value="second" id="useful" /&gt;
  &lt;/HTML&gt;
  
  // Second  DOM  
  &lt;HTML&gt;
  ...
      &lt;input type="text" value="first"/&gt;
      &lt;input type="text" value="second" id="useful" /&gt;
  &lt;/HTML&gt;
  </code></pre>
  
  <p><strong>Script:</strong></p>
  
  <pre><code>&lt;script&gt;
      alert($('#useful').val());
      // never select the first element (with the useless id)
  &lt;/script&gt;
  </code></pre>