I made an account just to say this.

I run impulse gaming wich is a mmorpg network. We run servers for things such as ragnarok online or lineage 2.

As an example ragnarok online uses 3 threads to run the game (map/character/login) and a fourth thread wich is obviously mySQL.

EVEN ON A LOW END SYSTEM! We can get 400-500 players online. This is with a P4 2.0ghz and 1gb of ram.

A decent multiplayer system with a server like fastlanes used would easily hold 5000+ players.

I hope this puts it into perspective for some people. If the server was having problems with 20 people on a high end PC such as that then I would not count on getting more than the 32 people that populace claims to support.

On the other hand if 3Dgamestudio supports c++ .dll support than there shouldnt be a problem with making your game first and then later on creating your own network code with c++ when you feel ready.