Wattage headroom
- Target 30–40% headroom over combined CPU+GPU draw to handle transient spikes.
- Examples: RTX 4070S + i5 = quality 650–750W Gold. RTX 4080S/7900 XTX + i7/i9 = 850–1000W Gold/Platinum.
ATX 3.0 and 12VHPWR
- ATX 3.0 PSU: Designed for 2x transient loads; preferred for RTX 40 cards.
- Cable quality: Use native 12VHPWR/12V-2x6 from the PSU, not stacked adapters. Seat fully until it clicks.
- Bending: Avoid sharp bends within 35–40mm of the connector to prevent heat/brown-out.
Rails, efficiency, and safety
- Efficiency: 80+ Gold or better for lower heat and noise.
- Protections: OCP, OVP, OTP, SCP are musts. Stick with reputable brands.
- Cable count: Use separate PCIe cables for high-draw GPUs if using 8-pin connectors.
Case airflow and thermals
Bottom-mounted PSU should have clear intake and a dust filter. Keep cables tidy to avoid blocking front intake to the GPU. Pair with two front intakes + one rear exhaust for balanced flow.
For vetted prebuilts with sane PSU choices, see our Best Gaming Computers guide.
