To get an idea of the number of users your server can support, regarding how they will work, please perform the following:
- execute the necessary application (s) that you intend to publish to the users, and calculate the memory usage by the user session involved,
- add at least 3 GB of RAM for server operation.
This operation will give an idea of how many sessions your server will support.
5 users will be using 3 applications: A, B and C.
A uses 200Mb, B uses 1Gb and C uses 300Mb = a user requires 1,5 Gb of memory.
5 users using 1,5Gb of memory = 7,5Gb
Add 3Gb for server operation = 10,5Gb is required, at least.
Obviously it will also need substantial bandwidth, as well as IO disks.