The short version
- An M4 Mac mini uses about 4 W at idle and up to 65 W at full processor load. A Mac Studio with M5 Ultra uses 9 W at idle and up to 385 W.
- Running an M4 Mac mini flat out for 24 hours costs about 29 cents at the average US home electricity price.
- AI work rarely holds a Mac at its maximum, so real costs are usually lower.
- An Apple Silicon Mac reaches high memory bandwidth, which is what AI output needs, at a fraction of a datacenter GPU's power.
1Mac mini power consumption
| Mac mini | Idle | Maximum |
|---|---|---|
| M1 (2020) | 6.8 W | 39 W |
| M2 (2023) | 7 W | 50 W |
| M2 Pro (2023) | 7 W | 100 W |
| M4 (2024) | 4 W | 65 W |
| M4 Pro (2024) | 5 W | 140 W |
| M5 Pro (2026) | 6 W | 145 W |
| M6 (2026) | 4 W | 70 W |
2Mac Studio power consumption
3What a day of work costs
Multiply watts by hours, divide by 1,000 for kilowatt-hours, and multiply by your electricity price. The average US home paid 18.3 cents per kWh in July 2026 (EIA); European prices are often higher (Eurostat).
| 24 hours at maximum | Energy | At 18.3 ¢/kWh |
|---|---|---|
| Mac mini, M4 (65 W) | 1.56 kWh | about $0.29 |
| Mac mini, M4 Pro (140 W) | 3.36 kWh | about $0.61 |
| Mac Studio, M5 Max (200 W) | 4.8 kWh | about $0.88 |
| Mac Studio, M5 Ultra (385 W) | 9.24 kWh | about $1.69 |
4Why Macs are efficient for AI
Writing text with a language model is limited by how fast weights can be read from memory, not by raw arithmetic (llama.cpp benchmarks). Apple Silicon puts fast memory right next to the processor and graphics, so a Mac reaches high memory bandwidth at a fraction of a datacenter GPU's power: Nvidia rates its H100 at up to 700 W (Nvidia).
That's why MLX Network is built on Macs. If you run MLX Node, you can cap how hard it works, pause it on battery and let it rest when the Mac gets warm. On a laptop, keep it plugged in while it works to spare the battery.
5Questions
- How many watts does a Mac mini use?
- An M4 Mac mini uses about 4 W at idle and up to 65 W at full processor load; the M4 Pro model up to 140 W. Apple lists every model's figures on its support site.
- Is it expensive to leave a Mac on all the time?
- Not for an Apple Silicon Mac at idle: a few watts, a few dollars a year. Under constant full load, an M4 Mac mini costs about 29 cents a day at the average US electricity price.
- Does running AI wear out my Mac?
- Macs are built to run under load and slow themselves down before they overheat. The main wear item is a laptop's battery, so it's best to run sustained work on power. MLX Node can pause automatically on battery.