Getting Started
Hardware & requirements
Arma Reforger's dedicated server is more CPU-intensive than most games, and the bottlenecks are different from what you might expect. Read this before buying or speccing hardware.
What affects performance
CPU single-thread
Primary bottleneck
The simulation, AI pathfinding, and entity updates run on a single thread. A faster clock speed and newer CPU architecture (higher IPC) matter far more than core count. This is the single most important spec.
Base server: 4–8 GB. Heavy modpacks add 2–4 GB each. 200 AI + heavy mods can push 20 GB. Running out causes crashes, not graceful degradation. Err on the high side.
Storage (SSD/NVMe)
Load times only
Affects server startup and mod loading. Once running, the server is in RAM — disk speed is irrelevant at runtime. NVMe shortens startups noticeably; HDD works but is slow.
Network upstream
Scales with players
Each player uses ~200–500 Kbps upstream depending on activity. 30 players ≈ 15 Mbps up. Most consumer ISPs cap out around 10–20 Mbps upload, which hard-limits your player count.
The dedicated server runs headless — no renderer, no display. GPU has zero impact on server performance. A cheap display adapter or integrated graphics is sufficient.
Spec tiers
These are starting points. Actual performance varies with mission design, AI count, mod complexity, and player activity patterns.
Starter 1–10 players · vanilla or 1–2 mods
CPU
i5-10600K / Ryzen 5 5600X
3.6+ GHz base
Standard 10–30 players · moderate mod list
CPU
i7-12700K / Ryzen 7 5800X3D
4.5+ GHz boost
Heavy 30–60 players · heavy mods or up to ~100 AI
CPU
i9-13900K / Ryzen 9 7900X
5.0+ GHz boost
Extreme 60+ players or 200 AI — read the reality check below
CPU
i9-14900K / Ryzen 9 7950X3D
best available single-thread
200 AI is an extreme workload. Arma Reforger's AI simulation runs on a single CPU thread. At 200 AI entities, that thread approaches saturation even on top-tier hardware — expect server frame rate drops and player rubber-banding at peak activity. This is a game engine limitation, not a Sitrep limitation. Bohemia Interactive's own servers carefully cap AI counts for exactly this reason. If you're designing a PvE mission with heavy AI, start with 50 and scale up incrementally while monitoring server FPS.
Sentinel overhead is negligible. In steady state, Sentinel uses <1% CPU, ~50–100 MB RAM, and minimal upstream bandwidth (heartbeats + command relay). It is not a factor in server performance calculations.
Home PC vs. dedicated hosting
Running on a home PC is convenient but has real limits:
✗Consumer upload speeds (10–20 Mbps) hard-cap you to ~20–30 players
✗Dynamic IP addresses can disconnect players if your IP changes mid-session
✗ISPs may throttle or deprioritize game server traffic
✓Works fine for a small group (under 20 players) on a solid gaming rig
For a serious milsim unit, a bare-metal or dedicated server with a static IP and guaranteed upload is worth the cost.