What limits one server from hosting 50 game servers (CoD4 for instance)? Say you have 16GB DDR, two quad core Xeon's... is it the operating system limits? I've been told not to overload a very powerful box, but I've also noticed that many hosting companies (the premium ones like Nuclear Fallout) host on quad core boxes w/4GB RAM.
So what exactly does prevent you from hosting tons of gameservers from one box?
PS, Is it better to run a game server as a service or in console mode?
Also, if anyone has any other tips on how to maximize game server performance (run smoother) feel free to share!