Hi there, I had some of the same questions myself and while Daren’s answer may be right, it may also be misleading for other readers. The difference is live video streaming vs VOD. If your computer is just restreaming a single live stream, then the hardware does very little, and so you can get away with what you are using. If you plan on using a VOD service, you will want to get more RAM, and invest in SSD hard drives.
Based off answers similar to Darren’s above, our company started off with dual i7 processors, 12GB ram, and 2X500GB HD in a RAID 0 configuration. We use exclusively VOD with 700 different videos, so almost everyone connected is watching something different. We found with that configuration, we could get around 80-100 customers max per server before having trouble.
After working with support, we identified the issue as being the HD, and upgraded to multiple SSD in RAID 0, 16 GB RAM and haven’t found the limit yet, but have had over 350 so far without any trouble. We also have found having multiple servers around the US helps users find one that works best for them, not because the servers are overloaded, but because it brings the data closer with less hops.
Hope this helps you, or someone else.