title: Cached, PHP generated Thumbnails load slowly
body: <p><strong>Question Part A</strong> ▉ (100 bountys, awarded)<br />
  Main question was how to make this site, load faster. First we needed to read these waterfalls. Thanks all for your suggestions on the waterfall readout analysis. Evident from the various waterfall graphs shown here is the main bottleneck: the PHP-generated thumbnails. The protocol-less jquery loading from CDN advised by David got my bounty, albeit making my site only 3% faster overall, and while not answering the site's main bottleneck. Time for for clarification of my question, and, another bounty:</p>
  <p><strong>Question Part B</strong> ▉ (100 bountys, awarded)<br />
  The new focus was now to solve the problem that the 6 jpg images had, which are causing the most of the loading-delay. These 6 images are PHP-generated thumbnails, tiny and only 3~5 kb, but loading relatively <em>very</em> slowly. Notice the &quot;<em>time to first byte</em>&quot; on the various graphs. The problem remained unsolved, but a bounty went to James, who fixed the header error that RedBot <a href="https://i.stack.imgur.com/FLWNX.png" rel="nofollow noreferrer">underlined</a>: <em>&quot;An If-Modified-Since conditional request returned the full content unchanged.&quot;</em>.</p>
  <p><strong>Question Part C</strong> ▉ (my last bounty: 250 points)<br />
  Unfortunately, after even REdbot.org header error was fixed, the delay caused by the PHP-generated images remained untouched. What on earth are these tiny puny 3~5Kb thumbnails thinking? All that header information can send a rocket to moon and back. Any suggestions on this bottleneck is much appreciated and treated as possible answer, since I am stuck at this bottleneckish problem for already seven months now.</p>
  <p>[Some background info on my site: CSS is at the top. JS at the bottom (Jquery,JQuery UI, bought menu awm/menu.js engines, tabs js engine, video swfobject.js) The black lines on the second image show whats initiating what to load. The angry robot is my pet &quot;ZAM&quot;. He is harmless and often happier.]</p>
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  <p><strong>Load Waterfall: Chronological</strong> | <a href="http://webpagetest.org" rel="nofollow noreferrer">http://webpagetest.org</a>
  <img src="https://i.stack.imgur.com/0LdLq.png" alt="enter image description here" /></p>
  <hr />
  <p><strong>Parallel Domains Grouped</strong> | <a href="http://webpagetest.org" rel="nofollow noreferrer">http://webpagetest.org</a>
  <img src="https://i.stack.imgur.com/KqdKq.png" alt="enter image description here" /></p>
  <hr />
  <p><strong>Site-Perf Waterfall</strong> | <a href="http://site-perf.com" rel="nofollow noreferrer">http://site-perf.com</a>
  <img src="https://i.stack.imgur.com/DuZzJ.png" alt="enter image description here" /></p>
  <hr />
  <p><strong>Pingdom Tools Waterfall</strong>  | <a href="http://tools.pingdom.com" rel="nofollow noreferrer">http://tools.pingdom.com</a></p>
  <p><img src="https://i.stack.imgur.com/pTbCb.png" alt="enter image description here" /></p>
  <hr />
  <p><strong>GTmetrix Waterfall</strong>  | <a href="http://gtmetrix.com" rel="nofollow noreferrer">http://gtmetrix.com</a></p>
  <p><img src="https://i.stack.imgur.com/DzIR3.png" alt="enter image description here" /></p>
  <hr />