Number Concurrent Users in Commercial MMO's

Most MMOs are sharded. Per shard, you'll get between 1,000 and 5,000 users. Each shard is typically broken up on several physical machines, typically by geographic area. The shards are then replicated to meet simultaneous load.

Some MMOs and most virtual worlds are single-instance. (EVE online, Second Life, There.com, etc.) Those typically have up to 50,000 or so simultaneously online in a single shard, but the users are again broken down across a large number of servers, again typically per geographic area.

The main reason MMOs do sharding is that it's much easier to design game content that works well for 1,000 people, than it is to design content that works well for 10,000 or 100,000 people. Think common areas, newbie areas, popular dungeons, ...

Oh I understand breaking it up into 'segments' although 'shard' is a first for me. But 1000-5000 is about what I was thinking. I just wasn't sure... :)

Thanks for your explanation!

'Shard' is a replication(copy) of an entire game World which has a unique set of player characters/avatars(who usually cant cross between 'shards').

A cluster of servers usually exists per shard, with most numerous machines running different geographical sections (areas) of that world).

Logical sectioning of the areas is often done to make smaller sections to cut down on the NxN update problem that usually saps processing performance.

You can usually quickly see the bottlenecking when there is some place in the game where alot of players suddenly show up (often only a few dozen players in the same vicinity).