Where the rig physically sits and whether there is enough power, cooling and stable electricity. In practice this, not the hardware, is what usually limits hosting.
How much power you need
A 4×RTX 4090 rig on a server platform: peak ≈ 2.2–2.4 kW, steady ML load ~1.8–2.0 kW. The average depends on utilization: ~1.0 kW at a realistic 50%, ~1.4 kW at 70%. Two rigs already peak at ~4.5 kW — that becomes the deciding question for the site.
Electrical — what to check
- Dedicated capacity: a flat has 5–10 kW (one rig at the limit), a house ~15 kW (1–2 rigs comfortably)
- A dedicated 16 A line with its own breaker and 2.5 mm2 copper cable — not a household outlet. One 16 A line (3.7 kW) covers exactly one rig: a second rig needs a second line
- Power quality: a stabilizer if there are sags and spikes
- Tariff ~6 rub/kWh → ~4,300 rub/mo per rig at 50% utilization and ~6,000 rub at 70% (night rate is cheaper)
Cooling and networking
- Almost all power becomes heat: a 2 kW rig heats like two space heaters — you need cold-air intake and hot-air exhaust, keep GPUs <80–83°C
- A dedicated router (not the ISP box) + a managed switch: a new rig plugs into a free port without stopping rented machines
- A UPS on the platform, network and router + auto-restart after failure (BIOS Restore on AC Power Loss) — power loss drops reliability and risks verified status
To start: one rig (4×4090) in a house or a separate room, a dedicated 16 A line, a UPS and summer airflow or AC. Scale out of profit.