To clarify (and I'll get the page updated to make this clearer) we're handling 185 requests/sec per server on average. There are other things not even touching IIS of course, so we're usually seeing somewhere between 2,400 and 3,000 requests per second overall coming into the network (not including WebSockets for various reasons).

Here's a grab from bosun taken just now of web tier load on those 9 servers: http://i.imgur.com/RJeEiYV.png

And here's a view of overall traffic coming into the NYC data center (except WebSockets): http://i.imgur.com/LV30989.png

Nick Craver Stack Exchange Developer & SRE