FileMaker limits are different than OS limits, BUT, it's ridiculous to setup a standard windows user box as a server for 30 clients.
Invest in the recommended hardware now and save a LOT of headaches in setup and maintenance later.
those are MINIMUMS.
Windows Server 2012 standard edition
8gb ram (RAM is cheap though, so I would max it out)
4 cores (chips are cheap too, get at least 8 cores)
Get a raid array set to RAID5 or RAID1+0, with at least 256gb of drive space.
I would never install FMS onto a plain windows OS box for 30 users.
Thanks for your comments Mike.
The basic idea (whatever the OS) is to use a RAID 10 SSD config (4x500Gb), Xeon 8 cores CPU and 32Gb RAM.
Of course I'd feel more comfortable using a Server OS. But purchasing the Server OS license + all needed CALS would be much more expensive than a Desktop OS.
Now, if you confirm FM connections are not limited by the maximum allowed concurrent connections on the OS side, we could go with a Server OS but no CALS and have best of both worlds...
CALs are completely different, FMS only uses inbound and outbound network traffic. There is no part of FMS that is related to seat based licensing on windows server.
FM connection sessions are still (for FM licensing) managed by the server, but it's inside of the FM environment, and not tied to windows at all. It supports 250 FMP clients.
You would only need seat licensing for windows if you wanted to use the server as a domain controller, exchange server, or other application that requires usage of CALs.
Note filemaker is not listed anywhere on the volume license lookup page.
Thanks for all the info, Mike!