We have a Ubuntu 14.04 server, running a standard WordPress + nginx + php5-fpm + mysql stack. Our traffic this weekend is higher than normal and even with increasing server memory and cpu power, we are still experiencing extremely high load which is affecting user experience. We use w3 total cache to cache pages, with separate mobile and tablet themes so all users get cached pages. Even with nginx set up to send cached HTML pages, numerous PHP workers are running. The cached pages are being served, but load still remains high. We need someone to examine the configuration and see if anything can be done. The cached pages work much better than actually logging in and making changes via the admin panel. Hopefully things can be optimized this weekend and fine tuned in future.