My Magento site is running extremely slowly on category pages which has a lot of products. I am presuming this is because of an image issue, however i have optimised and lossy compressed all images making them optimum for our site, furthermore the images on our category page are cached at a correct scale. Is there a reason why our site is taking 9 seconds to retrieve the images? I have also checked with our hosts who ran a tracert, confirming that it is not a server issue. It seems to be down to the instillation but i have no clue where to begin looking as I can't pin down what is causing this issue.
Please see waterfall chart below: