I’m currently building a new house and when its finished I plan on setting up a server for a few things :
-Home Automation server(Openhab)
-Beckhoff development server(Twincat 3)
-SQL Server
-Home Media server
-Minecraft server
-Mailserver
-Webserver
-Other random gaming servers
-Other random test servers to mess with
To be honest I have absolutely no idea how powerful this server would have to be.To me it seems that all these individual things don’t take up much resources.
I plan on building up the above over the course of time.
So I kind of need some advice what kind of specs are appropriate for this kind of system.
This is a system that will probably expand over time so might be useful to keep that in mind.
How much traffic are you expecting? That will determine what you need on the mail, gaming, web, and SQL server.
Are you going to be using Microsoft SQL Server or MySQL/MariaDB? For Microsoft SQL Server you’ll need a bit more resources than for the others, in my experience. 8GB of RAM for MSSQL whereas 2 to 8GB for the others.
I can’t speak for the gaming servers, never had the pleasure 
For my computer science projects, websites, mail server, databases, lab projects, and file servers I have a Dell T430 with 64GB of RAM and 2 Xeon 1.69 - 2.10Ghz processors and a R710 with 96GB of RAM and 2 Xeon processors that are 2.3Ghz each, I think. Can’t recall.
Spinning drives, RAID 5 and RAID 6. One is a KVM host and the other is an ESXi host.
I have limited incoming traffic, and generally 5 to 6 people using the resources at maximum in a given time. Generally it’s just me and another co-worker. Each VM has 1 to 8 GB each, depending on what it is.
most of this except minecraft and maybe another gaming server go well with multi threaded xeons. whats your budget and how expensive is power? how about space and noise? ryzen stuff is a option on a budget but no ecc support. the 1567 xeons are pretty cheap right now and so are some of the dual and quad socket boards, but not a lot of information about this is readily available. for ram, you are going to need a lot and the cheapest option is ddr3 ecc, but a lot of servers have not the best ram support and not always great return options on ebay and such. if you’re a baller and want it to just work you could buy a prebuilt(heard good things about puget systems) and then get to work on software right away.
so back to budget and how important is minecraft?
I don’t think there will be too much traffic, The biggest traffic load would probably be gaming and media and I think that’ll be with max 12 people at peak.
I’ll be using MySQL
Budget-wise I was thinking €1000-1500
Minecraft is not that important. I could start out with a system for everything else and get a dedicated machine for gaming servers later on.
Power is not really an issue,solarpanels. space and noise aren’t either since this will be placed in my attic.
I’ve been looking at this site:
https://www.creoserver.com/dell-r710lff-2x-l5640-sc-226ghz-48gb-ram
since it doesn’t have to be brand new hardware and this is a company relatively close to me(Its based in the Netherlands and I’m from Belgium)
I’m looking for pretty much the same thing for a similar use case. Want to run a SQL server, Minecraft server, and occasionally some other gaming servers. I checked out Puget systems but they all seem to be at least $1500. Is that about what I should expect to spend?