As Pegasaas Accelerator WP includes fast caching as a part of its web performance optimization functionality, and because Pegasaas Accelerator WP contains all of the optimization features that you will need to speed up your website, it is recommended that you do not have the WP Rocket plugin installed in parallel with Pegasaas Accelerator WP.  Running WP Rocket may cause a conflict which could cause your website to not operate as expected.