What PSU wattage do I need? A quick guide by GPU
Your graphics card decides almost everything here — it's the single biggest power draw in a gaming PC by a wide margin. Get the GPU's needs right, add a sensible allowance for everything else, and you'll land on the correct wattage without overpaying for watts you'll never use.
How to work it out
Add the peak power draw of your CPU and GPU — together they're around 80% of a gaming PC's total load — then add roughly 100W for the motherboard, RAM, drives, fans and coolers. That gives your real peak draw.
Now size the PSU so that peak sits at about 50–60% of its rating. A PSU is most efficient near half load, and that headroom absorbs the split-second power spikes modern GPUs produce. So a build that peaks at ~400W is ideally paired with a 650–750W unit.
Recommended wattage by graphics card
| Graphics card | Recommended PSU |
|---|---|
| RTX 4060 / RX 7600 | 550W |
| RTX 4060 Ti / RTX 5060 Ti | 550–600W |
| RTX 4070 / 5070 / RX 7800 XT | 650–750W |
| RTX 4070 Ti Super / RX 7900 XT / 5070 Ti | 750–850W |
| RTX 4080 Super / 5080 / RX 7900 XTX | 850W |
| RTX 4090 | 1000W |
| RTX 5090 (~575W) | 1000–1200W |
These are whole-system recommendations that already include a mainstream CPU and headroom. Pair with a high-end, power-hungry CPU (or plan to overclock) and step up one tier.
Why transient spikes mean headroom
Modern GPUs don't draw a steady amount of power. For fractions of a millisecond they spike far above their rated draw — a 300W card can momentarily pull 400W+. A PSU with no headroom can trip its protection and shut the system off mid-game, even though the average draw looks fine.
This is exactly why the '50–60% load' target exists, and why an ATX 3.0 or 3.1 PSU is worth having: those standards are certified to handle spikes up to twice their rated wattage.
What 80+ ratings actually mean
The 80+ badge measures efficiency — how much wall power reaches your components instead of being wasted as heat. The tiers run Bronze, Silver, Gold, Platinum, Titanium.
- 80+ Gold is the value sweet spot for almost every build.
- Platinum/Titanium cost more for small efficiency gains — worth it only for silent or always-on machines.
- An unrated, no-name PSU is the one component you should never cheap out on — it sits between your wall socket and every part in the build.
The 12VHPWR / 12V-2x6 connector
High-end Nvidia cards (RTX 4070 Ti and up, and most of the 50-series) use a single 16-pin 12VHPWR — now revised to 12V-2x6 — cable instead of multiple 8-pin plugs. Buy an ATX 3.0/3.1 PSU with a native 12V-2x6 cable rather than relying on the multi-plug adapter in the box, and make sure the connector is fully seated — a partial connection is the usual cause of the melting stories you've read about.
Don't overbuy
A 1000W unit in a 350W build doesn't make anything faster — it just costs more and runs slightly less efficiently, because it spends its life well below its efficiency sweet spot. Match the wattage to the build with a little headroom, and put the money you save toward a better 80+ tier or the GPU itself.
FAQ
Is a 650W PSU enough for an RTX 4070?
Yes. An RTX 4070 with a mainstream CPU comfortably runs on a quality 650W 80+ Gold unit. Step up to 750W if you pair it with a high-end CPU or plan to overclock.
Is a bigger PSU always better?
No. A PSU is most efficient at around 50% load, so a little headroom helps — but a hugely oversized unit just costs more and runs slightly less efficiently. Match the wattage to the build.
Do I need an ATX 3.0 power supply?
It's strongly recommended for modern GPUs. ATX 3.0/3.1 units are certified to handle transient spikes up to twice their rating and include a native 12V-2x6 cable for current Nvidia cards.