I'll chime in to help a bit here. I run HCFactions which is 125 slots, and I can handle 125 players at 20/ticks a second. Let me go over a few things. 1. Your power will come from your CPU and your HDD. For my server, I have a dedicated box (Intel i2600K) with 16GB of memory. I run CentOS with a ramdisk setup that does ramdisk saves every hour and backups every 12 hours. I still have an SSD in the box, so backups are fast. 2. Plugins make a huge difference, as does your setup. If I were running a creative server I imagine I could get to 200 or more players easy, maybe 400. The reason for this is no monsters, and minimal plugin overhead. For a survival server, plugins can make or break you. As an example, I had a single custom coded plugin that prevented me from getting over 80 players. I had it optimized and no lag to 125. You have to begin thinking of plugins in what events they monitor. NoCheat for example monitors movement, fighting, and block placement. This means it is basically triggering on every event a player makes. Big CPU user, but for most of us PvP server owners, something you'll need. Orebfuscator manipulates at the chunk level, another big CPU user, but something you'll need in a PvP environment. Using a plugin that has regions? It is going to track player movement. Using a plugin that modifies combat values? It's going to fire off on any combat event. Learning the event system is your first step to understand how plugins alter the performance of a server. Using bukkit's debug timing option allows you to peak at what plugins are using the most CPU time and help you optimize. 3. Bandwidth. You can't run a big server from your home. You will need a 100mbs connection ideally located near a big data center. Find a good dedicated server host. 4. DDOS protection. Yep, you are going to get hit. Are you okay with having your server hit hard for a couple hours or do you want to use a professional host that puts DDOS protection at the firewall level? It'll cost you if you want it. I hope that helps. I did some heavy modification to the bash scripts available on the various wiki's to meet my needs. I have no issue sharing how I did things. One of these days I'll write a guide to prevent others having to spend 100s of hours like I did on setting up a server (I had never touched linux prior to starting my server). Also, I am happy to refer you to my host. I pay $179/month for my setup, which is a bit of a steal.