Just as an update, there are modular switches like the the Cisco nexus 5000 series that do have fabric extenders, rather than stacking cables. This is is a high end data center switch though. The fabric extenders generally look like a switch, or extend the switch fabric to a chassis with VM blades in it.
The answer to this guys question was simple. YES! a one gig link between two switches, with 10 end users pulling from a file server simultaneously at 1Gb port speed. Unless you have QOS on your network, or some type of bandwidth throttling on the server you have a bottleneck. There is no question of this, and no testing or stats needed. I agree that you should be monitoring, but this should have been obvious to whomever designed your network. Assuming its a Microsoft file server its gonna try to shove files down the pipe as fast as it can. It will find the max bandwidth it can use and throttle its available bandwidth. Now, factor in your other traffic on the network as well. In many networks the bottle neck to the server would be the 2GB port-channel from the server to the switch. It would only take three 1GB users to throttle the available bandwidth for that server. At this point the bottleneck might be barely noticeable to the end users but it is there. A bottle neck is not really a problem until it brings performance levels down to an unacceptable level.
