Long Content Download after fixing time-to-first-byte

I have a magento site (http://caribecomp.org) that I have been having issues with. I was having a long Time to First Byte issue where it was between 4 and 8 seconds. I have since corrected that, however in its place I now have a Content Download time of the same length.

http://www.webpagetest.org/result/130805_KM_ZPN/1/details/

My Time to First Byte is now “OK” but I have this huge “Content Download” time instead and its making the page take a long time to start to load. It doesnt make any sense since the size of for that call is only 56KB. It should not take 3 seconds or more on Cable to download 56KB of content.

I have php-apc, memcache, gzip, apache expires, magento caching, all enabled. They do not seem to correct this issue however. If you look at the load AFTER that initial “content download” problem the site loads very very fast. These tests just dont show me what is taking this site so long to load after the first byte of the first request.

Anyone else see this, and fix it?

It looks like you “fixed” the long time to first byte by flushing some of the content early so the browser gets some headers and a tiny bit of html but the full html still has to wait until whatever is slow on the back-end finishes.

You can make the early flushing more effective if you can include more of the head and external resources so the browser can get a head start but fundamentally it’s still taking ~3 seconds on the server to generate the HTML and it’s worth fixing that for real.