I am talking http requests. I have found some reports but usually the reports are biased one way or the other. I'm juts looking for a simple answer wchich is really not in any of the reports I have found.
There are a number of papers at the MS site which talk about this. I have verified myself that "IIS out of the box can only handle 10 concurrent users". When you have 10 requests that take a bit longer, say going against a database, any further requests are saved in queue. As the 10 requests are completed the number of requests in the queue do down. This setting can be changed within the registry.
Maybe "concurrent users" not quite the right term. Perhaps it should be called "concurrent threads" or "concurrent active users".
The point of my research is not to bash IIS or *nix. It's just part of a program to educate about stress/performance testing and to dispell myths about the two systems. Believe me IIS can blaze through normal html files and simple ASP stuff even if there are only 10 active threads.
We have many Unix boxes but mostly for Lotus Notes and DB stuff.