I realize that has already been asked adnauseum, but wanted to bring it to light again incase anything has changed.
We're looking at setting up Bamboo, Crucilble, FishEye, Greenhopper, and Jira. System requirements are a good start, but not overly helpful in that they don't say anything about how many users are being accounted for with the requirements.
The fact is that we and many other companies need to submit requirements to those in organization responbile for provisioning servers and databases. It makes us look silly to ask for servers/DBs based on the listed system requirements and then find out that we need to have 16GB RAM instead of 4GB or 4 CPU cores instead of 1 after reaching X (mystery number) of concurrent users.
I've read the suggestion that we find this out on our as part of the trial process. This still isn't very helpful as it wastes our time and still makes us look silly if we need to go back and ask for beefier servers.
It would be extremely helpful if included with the requirements were guidelines as to how things will likely need to scale. e.g. 1 more CPU core per 10 users, etc.