Reports / Campfire vs Slirc
Campfire vs Slirc
Same job, group chat on our own hardware. Very different footprint.
Campfire is an excellent alternative: open source, self-hosted, runs one command, and you get the code. We measured both products side by side to see what the same job costs on our own hardware.
The numbers
| metric | Campfire | Slirc |
|---|---|---|
| RAM, idle | 1.62 GB (76% of its own 2 GB cap) | ~20 MB total (13.6 MB app + 6.6 MB Ergo) |
| CPU, idle | 2.03% | ~0.1% |
| processes | 220 | 12 |
| image size | ~917 MB (877 MB app + 40 MB Redis) | ~135 MB (97.8 MB app + 36.7 MB Ergo) |
| extra services | separate Redis container | none |
How it adds up
- RAM: 81×
- CPU: ~20×
- processes: 18×
- disk images: 6.8×
Capacity
Campfire sits near its own 2 GiB cap before anyone connects. Slirc's whole stack uses about 1% of that, so the same cap holds roughly 80 Slirc stacks.
Campfire alone eats 1.6 GB of its machine's 31 GB. Slirc's whole stack fits comfortably on its 3.8 GB host.
Load
Synthesized 250 concurrent IRC clients against the local Ergo instance: all registered and joined, then chattered at ~210 messages/s for 40 seconds, about 52k outbound deliveries after fanout.
| metric | 250 users (measured) | 500 users (modeled) |
|---|---|---|
| Ergo RAM, idle | 17 MiB | 17 MiB |
| Ergo RAM, during load | 39 MiB | 60-80 MiB |
| Ergo CPU, sustained | 5-15% of one core | ~10-30% |
| Ergo CPU, burst spike | ~49% of one core | under one core |
| messages handled | 8.4k in / 52k out | ~2× |
This is the chatty worst case, every user talking continuously. Real groups sit mostly idle at the WebSocket relay, so actual capacity is well above the model.
Recommended server
Same ladder shape Campfire publishes (they start at 250 users / 2 GB / 1 CPU). Slirc's numbers start from the measured load above and scale for the whole stack, app relay, Ergo, Caddy, and headroom, not bare Ergo. Hetzner Cloud ARM servers hit these tiers out of the box, prices included.
| concurrent users | RAM | CPU | Hetzner | est. price |
|---|---|---|---|---|
| 250 | 1 GB | 1 CPU | cax11 | ~€7/mo |
| 1,000 | 2 GB | 2 CPU | cax11 | ~€7/mo |
| 5,000 | 4 GB | 4 CPU | cax21 | ~€13/mo |
| 10,000 | 8 GB | 8 CPU | cax31 | ~€25/mo |
Memory stays the cheap axis (Ergo idles at ~17 MiB and peaks under 40 MiB for 250 chatty users); the growth curve is CPU and the WebSocket fanout, which is why it climbs slower than Campfire's ladder.
Method
Both hosts measured 2026-09-07 with podman stats (three samples, two seconds apart), podman images, and podman system df. Load numbers measured 2026-09-15 with a 250-client synthetic script against the local stack.