We have just migrated from vBulletin 3.8 to xenForo and at the same time upgraded our server to much more powerful one. Our virtual server's specifications: CentOS 6 64bit 2 processor cores 8 Gb RAM 100 GB SSD Apache with Zend Opcache MySQL Our forum has peaks of 2400-2800 visitors at the same time, so the traffic is quite heavy. When the peaks occur, the forum becomes almost unusable. Currently with about 1200 visitors, the server loads are around 8-9. I have crawled through this community forum and tried almost every trick proposed here, but nothing seems to work. Our my.cnf: Relevant parts from Apache conf file: Does anyone have any propositions to what do to next to get the forum run faster?