How much electricity does running AI locally use?
Less than most people expect. Apple measured an M5 Ultra Mac Studio at a maximum of 385 W from the wall, so even at full load around the clock it uses about 281 kWh a month, roughly $56 at $0.20 per kWh. A single NVIDIA RTX 5090 is rated at 575 W, and an H100 SXM at up to 700 W, before the rest of the server.
Real use is lower than these maximums because machines sit idle between requests.
Lower power also means less heat and noise: a Mac cluster can sit in an office instead of a server room.
| Hardware | Max power | Monthly energy at full load |
|---|---|---|
| Mac Studio, M5 Max | 200 W (measured) | 146 kWh |
| Mac Studio, M5 Ultra | 385 W (measured) | 281 kWh |
| NVIDIA RTX 5090 (GPU only) | 575 W (rated) | 420 kWh |
| NVIDIA H100 SXM (GPU only) | 700 W (rated) | 511 kWh |
Sources
Updated