Headless Clients (or HC's) can be used to offload AI calculations from the ARMA3 server, helping improve performance by spreading the processing load across more CPU cores. Less calculations on the main thread of the game means higher FPS for your players - and that's always a good thing. Particularly where heavy mod-loading is involved, or high amounts of AI units, Headless Client's are a huge boon for the server operator. (Note - your Headless Clients are also bound by the same limitations as your server - so if you find you need more Memory, or more CPU space, please make sure you upgrade your ARMA3 server in our client area for a more snappy response time!)
How to...
The headless clients run via AMP are launched when the server is started, and terminated when the server shuts down.
In the Arma Server Settings menu, set the number of clients you want to launch under “Headless Clients To Launch”.
To allow these Headless Clients to join - make sure you do not remove the "Local Headless Client IPs" 127.0.0.1 setting - this is required. Note that, as a failsafe, if the server is not successfully started within 3 minutes, the headless clients will not be launched.
Any mods listed under “Load Mods” within the Arma Server Settings area will be passed to the headless clients so that they can connect to the server. If you are instead using a parameters file to load mods for the server (under “Use Server Startup Parameters File”), you can also use a separate parameters file (called hc_parameters.txt) to pass the mods to the headless clients. See the “Use Headless Client Startup Parameters File” setting.
Further Reading
Bikeys and Mods - How you protect your modded ARMA3 Server from Cheaters
First-time Setup of your ARMA3 Dedicated Server
How to load Mods on your ARMA3 Dedicated Server
