Disclosure: I provided an example on the linked question
I think this straddles the line of "pre-purchase" information. This question has already purchased the hardware and is really asking a configuration question: How many players can the hardware support.
However, the question could easily be adjusted to something like: "I want to support X players, what hardware do I need?" This would lead to the same answer I provided and would very clearly be a pre-purchase question.
Regarding the comment by ArtOfCode on where the line should be drawn, I think that depends on the requirements of the question and if it is truly a request for information about a possible purchase. If the question is getting into configuration, such as
- How do I configure the server to use all of my cores
- How do I limit ram usage to only X
Then it is headed off topic. These are clearly not related to the hardware or performance of the system.
The line, to me, is at the point where the user is tweaking a setting to get better performance.