title: Huge array takes more memory space than it should
body: <p>Currently my app uses around 7 MB memory.</p>
  
  <p>The array appears to use 700 KB if I check it size with <code>strlen(serialize($array))))</code>.</p>
  
  <ul>
  <li><p>If use this array within my app, and check memory usage (with <code>memory_get_peak_usage()</code>) I get 14 MB.</p></li>
  <li><p>If I don't use it, I get 7 MB.</p></li>
  </ul>
  
  <p>If this array takes 700 KB serialized, why does PHP need 7 MB for this variable? Or am I doing the benchmark the wrong way?</p>