Private server bandwidth and memory.

[_tao4229_]

2gigs ram, any dual core over 2ghz, 5/5mb/s internet (or 10/10+ for avg 400-500+ players)
that should be it.
2 gigs ram if you're loading everything instead of inlining it, server should be using around 200megs-600megs (really depending on what youre hosting) for a full server. the more ram the better even if its unused, gives the kernel more memory that it needs.
bandwidth shouldn't be a big problem if its hosted from a server, it shouldnt even a break privately owned internets bandwidth limit unless youre hosting more than Conquer does on 3 servers -.-

[KraHen]

It depends pretty much on your source. For example, HybridCO ran on like 768 MB ram or something like that, with a single-core processor, hosted from home, and it was good.

[LetterX]

Originally Posted by ElDeRnEcRo

It depends pretty much on your source. For example, HybridCO ran on like 768 MB ram or something like that, with a single-core processor, hosted from home, and it was good.

and it also ran on what I mentioned above in my earlier post =D