Rabid Snail--
I have been delving into this server administration thing ever since UT2K3 was released. I have been doing research on the ina-community forums (and elsewhere) just to make sure that my server is running smoothly. Epic/Digital Extrems have indicated that one needs about 35kbps per player. They also set the minimum system for 16 players at 600 MHz with 256 MB RAM. I find that very minimal, though I run my server with a 1 GHz Duron with 384 MB SDRAM. It has had NO problem keeping up. I can actually do a little e-mail and surfing while running the server. I've actually done this form time to time to see if/how much performance suffers (not at all, really). Keep in mind that these figures are for a dedicated server. The only thing a dedicated server is doing is performing a bunch of calculations and reading/sending results out over a network connection. One only needs a really powerful rig when it must be concerned with performing all the GRAPHICS duties required at the client side. So, if you plan on playing from the same machine, then YES, you will need one boss computer.
For 16 players to have enough bandwidth multiply your 35kbps X 16 = 560kbps (or .560Mbps). That would be for both up and down stream. Myself, I'm running with SDSL 768kbps (768 up AND down) and again, I have had good performance even when the server is at a full 16 players. I wouldn't increase the player limit above that as to give myself a little extra overhead to IM or play on another server myself. I do make it a point, however, to avoid downloading Windows updates and such while people are playing.
Epic is saying that the game is playable with anything under 300. I say ideally, your ping should be less than 200 to be useable-- <150 to really be enjoyable. Pings, however, are mostly out of your control. Pings are not based on your connection speed as much as it is your ISP's connection to a trunk and how many hops packets must make to their destination. So, it just depends upon how good both the host and client ISP's are and number of hops between them.
As far as RAID is concerned, it might make games load quicker, but keep in mind, the games don't really start until everyone ELSE's games are loaded, so there isn't much of a requirement there unless all of the players have RAID and are tired of waiting on the server to load up.
So, Rabid Snail, the short answer to your question is YES. You should have no problem hosting 16 players (at least in UT2K3) with your rig and your bandwidth.
I will add this though: Cable connections are NOT ideal for hosting game SERVERS. Because of the shared nature of those lines, bandwidth can take a dump at any time. And a drop off in bandwidth, even for a moment, can make everything screw up and necessitate a resync or even a reconnect. With xDSL, you get all the bandwidth you pay for and there is extremely little chance that you will lose netspeed because that chunk of bandwidth has been allocated to that ONE line.
