Boost Module problem in logged in user
Boost 
  Boost provides static page caching for Drupal enabling a very
  significant performance and scalability boost for sites that receive
  mostly anonymous traffic.


I am not sure if Boost can be used for authenticated users as well. Boost will capture rendered HTML pages and store them and when a request comes for same page instead of overloading the server with PHP execution it will send the already compiled HTML pages which will greatly increase performance.
Auth cache is an alternate that allows caching for both authenticated and anonymous.