How to calculate the capacity of a local server?

Question

Server equipment

Good day. I serve in the army in the automation department. At the headquarters, all machines are local, and at some point, the information security officer and I came to the conclusion that it was necessary to make all these machines local. And at this point, the question arose with the selection of the physical server part.
If someone does not know, then no one in the army will give you what you need to make everything work great. And so the computer was found plus or minus powerful (i5 4 generations, 8 GB of RAM and 2x1 TB of railway). The plans are to buy 8 more RAM, since there are free slots.
This machine will act as a domain controller, it will deploy the Kaspersky control center (for monitoring threats and updates) and secretnet (information protection tool), for monitoring device connections and printing. In total, there will be about 65 machines in the network.
The question is, is it rational to use such a computer for these tasks in the absence of other options? If not, what are some examples of relatively cheap equipment to implement tasks?

Answer 1

Who will sell you licenses for AD?
Why is kaspersky used if it is not safe?
In general, a PC is fine

Answer 2

AD starts on any coffee maker that meets the minimum requirements of the selected
Windows

Answer 3

It is completely pointless for the server to buy more RAM for such a task.
win2016 server as a domain controller will work almost at 512 mb, kaspersky sequrity will require 1 GB
for the described task, you need to allocate the slowest machine, and correctly said - you also need a backup
ps I would also virtualize everything to the maximum, inside the virtual machine the server will be more mobile ', i.e. the death of a machine will be easier to bear, and not only a domain server, but in general any server is better to be transferred inside virtual machines, and you can also split it up if licenses allow.
storing files inside a virtual machine is not necessary, although it is preferable to keep it on a separate machine
for some reason, many people combine the server with file storage in one bottle, and then they get a lot of problems with the transfer.