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Most online PSU calculators either pad the result massively or haven’t been updated for the latest graphics cards. This one adds up realistic peak power for each part and gives you two figures: the minimum that will run the system, and the size we’d actually recommend buying for efficiency, quiet operation and headroom for spikes.
How the estimate works
- CPU: the maximum package power at stock settings (AMD PPT, Intel PL2/maximum turbo power) — not the lower “TDP” on the box.
- GPU: the manufacturer’s reference total board power. Factory-overclocked cards can draw 10–20% more.
- Everything else: about 60 W for the motherboard, 10 W for memory, 7 W per drive, 3 W per fan, 10 W for an AIO pump and 20 W for heavy RGB.
The minimum PSU is peak load plus 10%. The recommended PSU is peak load plus 30%, rounded up to the next common size — which keeps a quality unit in its most efficient range at gaming load.
GPU power reference
| Graphics card | Board power | Typical PSU for a gaming build |
|---|---|---|
| GeForce RTX 5090 | 575 W | 1000–1200 W |
| GeForce RTX 5080 | 360 W | 850 W |
| GeForce RTX 5070 Ti | 300 W | 750 W |
| GeForce RTX 5070 | 250 W | 650 W |
| GeForce RTX 5060 Ti | 180 W | 550–650 W |
| GeForce RTX 4090 | 450 W | 850–1000 W |
| GeForce RTX 4070 Super | 220 W | 650 W |
| Radeon RX 9070 XT | 304 W | 750–850 W |
| Radeon RX 9070 | 220 W | 650 W |
| Radeon RX 7900 XTX | 355 W | 800–850 W |
Figures are reference specifications published by NVIDIA and AMD. Always check the recommended system power for your specific card model.
FAQ
Is a bigger PSU wasteful?
Not really. A quality PSU is most efficient around 40–60% load, and an oversized unit often runs its fan less. The main cost is the purchase price.
Do I need an ATX 3.1 power supply?
For RTX 40- and 50-series cards that use the 12V-2×6 (12VHPWR) connector, an ATX 3.x unit with a native cable is strongly recommended. It’s rated for the brief power spikes these cards produce and avoids adapter dongles.
Does 80 Plus rating affect wattage?
No — the rating is about efficiency (how much power is wasted as heat), not capacity. Gold or better is a good baseline for gaming PCs.
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