To host Arma 3 Epoch you require a dedicated server - whether you choose to rent an Arma 3 server from a Game Server Provider [GSP], rent/host your own Dedicated Server [DS] or purchase your own Dedicated Server and have it co-located is entirely up to you.
An Arma server rented from a GSP will already have the minimum requirements, performance will be dependant on the GSP, some have better equipped servers than others.
Recommended Dedicated Server Specifications:
|CPU:||3.0Ghz+ 4c4t Quad Core+|
|HDD:||512GB+ - Most Dedi's have 1TB+ HDD's these days, some have optional RAID. Remember you still need space for your OS and any mods you plan on using.|
|SSD:||120GB+ - SSD's are becoming more commonly available from DS companies and many people already have them in thier own dedicated servers.|
|Network Link:||100MBit+ - Most Dedi's come with a port speed of 1Gbit which is limited by your contract with them - 100/200/300Mbit throughput is common, 1Gbit is usually an extra cost over and above the basic rental of your dedicated server.|
|Bandwidth:||1TB+ / Month - Bandwidth requirement is dependant on everything you do with your dedicated server, 1TB/month is the absolute bare minimum I would recommend for running your own dedicated game server|
|OS:||Linux or Windows Server 2008/2012|
HDD or SSD? - Either or both, it depends on what is available to you - if you run the server + redis DB from an SSD your server load times may be faster, Arma is a CPU hungry game and overall it is CPU cycles (Ghz) that effects the server most.
Windows or Linux? - That is entirely up to you,.
Linux is a free open-source operating system, Arma3 support for linux is ever-increasing, Epoch already supports Linux.
Windows Server is available in two flavours that are supported by Arma3: 2008 or 2012. There have been mixed performance reports about which version is better regarding Arma hosting. With Windows you will have to pay a licencing fee to your host company, this cost varies but is usually around £/$/€ 20-40 per month ontop of your server rental cost. Some hosts will let you opt to install your own licenced edition of Windows Server on your dedicated server - This is not a cheap option as Windows Server 2008/2012 is fairly expensive to licence.