SharePoint Farm 2013 Topology in Production

Question

In our farm, Current total users are 150 and unique users hardly 30+. Data size we have is currently 50 GB. Since this data clearly tells very less no of users and less hits and less size, how many servers you recommend in farm?
Do you recommend having
A)3 servers in farm ( 1 app, 1 wfe & 1 sql)
B)2 servers in farm ( 1 app & wfe and 1 SQL)
We would like to go with B, we planned and decided to go with this option B
 with single SharePoint server and if it fails we can take down time and bring back , by doing this do we have any other issues?
Considering the SharePoint server license commercial aspect we are planning to have single server in farm where we load that single server with high end hardware configuration. By practing do we get into any other issues, if so what kind of issues. Please
elaborate. I am really looking for this answers in detail.
I understand issue of single point of failure of the SharePoint server, but we take this into consideration and we take incharge of it by taking downtime. But what are other strong issues that will not say to Option B.
Thanks, Ram Ch

Answer 1

Here is a
link to the "Topologies for SharePoint 2013" poster. (warning: PDF). You will note that the 2 server topology is certainly listed (with one SharePoint box running all SharePoint services and a second server for the SQL Databases). That server
topology is listed as supporting a small farm, and a small farm according to MS will support up to 10,000 users!! How do they get 10,000 users? There is an assumption that only about 10% of users will ever be active at the same time, so their 10,000 number
really means 1000 active users. And by active, they mean an average of one mouse click per 60-90 seconds. So if 1000 users click about once every 60 seconds, that means a request rate of 16 per second, which a decent server should be able to handle.
So, a single SharePoint box should be able to handle 150 users without any issue at all, provided the server has enough memory and such to properly run all the necessary services (if the disk is thrashing due to low memory while a search crawl is running,
you're going to have issues, for example).
Mike G.