Hi Anon -
Thanks for writing!
Regarding our connection, we have redundant 100 Mbit connections from multiple tier 1 providers. Currently, we're using roughly 1/4th of our current capacity, and can bump that up if the need ever arises. It's very unlikely that the addition of any one client will ever cause that to happen, however, and we'd be able to make arrangements ahead of time should it look like we need to increase capacity.
As for average bandwidth load per individual server, I honestly don't know. However, the real bottle-neck that comes up on a per-server basis is CPU and memory usage, not bandwidth consumption. Anyone who is using enough bandwidth to make consumption an issue will likely have upgraded to a dedicated server (or multiple dedicated servers) far before it impacts other customers.
To manage CPU load and memory usage, we carefully balance the number and type of customers on any individual server in such a way that no shared server is overloaded. It's fairly trivial to move a customer to a different server with no downtime being involved (customer data isn't even stored on the web server itself, but on a separate filer).
Any customer who hits their shared server hard enough to impact other customers will usually upgrade to a dedicated server for lower cost and greater flexibility.
If you have any other questions, let me know. :>
- Jeff @ DreamHost
- DH Discussion Forum Admin