EVE Online, developed by CCP Games, boasts one of the largest server clusters of any MMO, supporting over 5,000 solar systems and millions of objects, all in one giant shared universe.Their server system is so robust that they schedule a one hour down time every day to run backups, and the system can handle up to 25,000 players (and sometimes more) without collapsing.

|Despite supporting over 50,000 simultaneous users, the server cluster requires just one hour of downtime a day for maintenance.|Only one hour a day of maintenance is required for this monster server cluster, which is designed to scale to support over 50,000 simultaneous users.|With over 50,000 users logged in at peak times, the server cluster can cope with node failures, hardware crashes, and still keeps on going - with only an hour of maintenance a day.|A daily downtime of an hour a day is all that's required to keep this giant server cluster running, supporting over 50,000 users at peak times.[/spin]

The requirements of EVE Online are such that running private servers becomes impossible - unless you have hundreds of 64bit processors and some ultra-fast solid state storage.

However, the lack of EVE Online private servers benefits players and helps with the game experience.However, the lack of EVE Online private servers benefits players and helps with the game experience.No other game boasts as many simultaneous users in such a large shared universe, and this is the real appeal of EVE Online. Because EVE Online runs on a single cluster, there's never a choice, like in World of Warcraft, or City of Heroes, to decide which server you're going to be on based on the server your friends are on.

You're either on the Tranquility server (if you use the English language interface) or the Serenity server (if you're using the Chinese language interface), and there are usually ten thousand or more players on simultaneously to interact with. By logging into the test cluster, Singularity, players can test upcoming features and EVE Online ships, and help shape the game's development.

By contrast with World of Warcraft, there are dozens, if not hundreds, of private servers out there, that will let anywhere from a hundred to maybe a thousand players log in simultaneously. For WoW, this is an opportunity to "grind in private"; if you tried doing that on EVE Online, you'd have a hard time hooking up with other players at all, due to the massive size of the universe to explore.

An EVE Online private server would require so many expensive, high end, complex servers that - for many people - it would be cheaper to buy a supercomputer from Silicon Graphics or Cray.