If you access TN datastream content directly through url on Fedora server, time of loading image is ~5ms and going through Drupal's datastreams/TN/contents is ~400-500ms+ depending on number of modules loaded (by disabling XML Forms time drastically goes down). Also, directly using tuque library functions in PHP code (not using anything Drupal related), object load time is also ~300ms+.
xdebug trace of $repository->getObject("dummy")
>getDatastream("TN")>content shows long period before curl_exec is done executing for http://server:8080/fedora/objects/dummy?format=xml
Major problem we have is long page load time when browsing all objects using islandora solr search.
Our solr-fedora server is separate from Drupal but wget for object from fedora server takes ~10ms.
Any input for optimizing page load time is valuable.