How to choose a power supply (PSU)
6 min read · Updated 2026-10-06
How many watts?
Add up the CPU and GPU power, add about 100 W for the rest of the system, then leave 30–40% headroom so the PSU runs cool and quiet and handles power spikes. Our PSU calculator does this for you.
- Entry builds (RTX 4060 / RX 7600 class): 550 W.
- Mid-range (RTX 5070 / RX 9070 class): 650–750 W.
- High-end (RTX 5080 / RX 9070 XT): 850 W.
- RTX 5090: 1000 W or more.
Efficiency ratings
80 Plus Bronze is fine for budget builds; Gold runs cooler and is the usual choice for mid and high-end PCs. The rating is about efficiency, not quality on its own: buy from a well-reviewed model line.
ATX 3.1 and the 16-pin GPU cable
Recent NVIDIA cards use a 12V-2x6 (16-pin) power plug. An ATX 3.0/3.1 PSU has this cable built in, so you avoid adapters. Push the plug in fully and avoid sharp bends near the connector.
Features worth having
- Modular cables: only plug in what you use; easier cable management.
- Warranty: 7–10 years usually means a better unit.
- Size: SFX units for small cases; check the case's maximum PSU length.
