At Zodiac Media we are big fans of NGINX and Apache2. Personally I swing more towards NGINX, as the configuration is super simple and very transparent. Like all web servers, it needs to be tuned to get the best possible performance out of it. NGINX was designed to deal with the C10k problem, this refers to the optimization connections so that they can handle client connections in the range of ten thousand (and over) simultaneously. This can be fairly complicated if you are not used to using the command line. If this is not the case, then get in touch, this is our bread and butter. These configuration settings should allow you to get every bit of performance out of your NGINX setup.