Quintupling the workers makes it much more responsive. Thanks.
I am also getting some serious lag on the rendering in the library browser. I'm rendering about one problem every 2 minutes. However, If I click "Try it", the problem pops up instantly, though.
I tried tinkering with the settings in the above-mentioned file, but no success in improving the rendering times in the Homework Set Editor or the Library Browser.
Would you have any other recommendations to consider?
Usually issues with the Library Browser have to do with the $server_root_url not being set correctly. Look at
Also check to see what error/warning messages come up in your browser (e.g. with Chrome look at the console under developer tools).