Data and measurements from our catalog, checked against each manufacturer's spec sheet.
- Add up the CPU and graphics card draw, add the rest of the build and leave 35% headroom, like the configurator does.
- If the graphics card maker asks for a bigger power supply, go with the maker.
- 80 Plus measures efficiency, not quality: a Gold unit wastes less energy as heat than a Bronze one.
- For a new graphics card, pick an ATX 3.1 power supply with the native 12V-2x6 cable.
- Look for OVP, UVP, OCP, OPP, SCP and OTP protections and a brand with a good warranty.
1How many watts do I need? A quick calculation
Do the same math as our configurator: add the CPU's TDP, the graphics card's power draw and about 85 W for the rest of the build (motherboard, RAM, SSD, fans and USB). Multiply that total by 1.35 (35% headroom) and round up to the next 50 W power supply. Finally, compare it with the minimum power supply the graphics card maker asks for and go with whichever is higher.
Headroom does three things: it handles the spikes of modern graphics cards, which last milliseconds but go far above their average draw; it keeps the power supply in its most efficient, quietest range; and it leaves room for a more powerful graphics card in the future.
Here are some examples with parts from our catalog (using each card's highest-drawing model):
| CPU + graphics card | Estimated draw | With headroom | The GPU maker asks for | Recommended PSU |
|---|---|---|---|---|
| Ryzen 5 9600X + RTX 5060 | 259 W | 350 W | 550 W | 550 W |
| Ryzen 7 9800X3D + RTX 5070 | 455 W | 650 W | 650 W | 650 W |
| Core Ultra 7 265K + RTX 5070 Ti | 510 W | 700 W | 750 W | 750 W |
| Ryzen 7 9800X3D + RTX 5080 | 565 W | 800 W | 850 W | 850 W |
| Ryzen 9 9950X3D + RTX 5090 | 855 W | 1200 W | 1000 W | 1200 W |
Watch out with Intel K chips: their 125 W TDP is the base power, but in long all-core workloads the Core Ultra 7 and 9 and the i7 and i9 can reach about 250 W. It doesn't happen while gaming; if you'll render or compile for hours, go one step up on the power supply.
Try your exact combination in the configurator: it does this math with every part you pick.
280 Plus Bronze, Gold or Platinum: what changes
80 Plus certification measures how much of the energy the power supply draws from the wall actually reaches your parts; the rest is lost as heat. These are the minimums at 115 V (the US grid) by load:
| Certification | 20% load | 50% load | 100% load |
|---|---|---|---|
| 80 Plus Bronze | 82% | 85% | 82% |
| 80 Plus Gold | 87% | 90% | 87% |
| 80 Plus Platinum | 90% | 92% | 89% |
| 80 Plus Titanium | 92% | 94% | 90% |
A Gold unit uses a little less electricity and runs cooler, so its fan is usually quieter. But 80 Plus doesn't measure the quality of the components, the protections or voltage stability: there are very good Bronze units and mediocre Gold ones. That's what technical reviews and the warranty are for; mid-range and high-end power supplies usually carry 7 to 10 years or more.
You'll also see Cybenetics certification (ETA for efficiency and LAMBDA for noise), which tests the power supply across many more loads and is stricter. In our catalog, 30 of the 37 power supplies are Gold or better.
3ATX 3.1 and the 12V-2x6 connector
ATX 3.0 and 3.1 are the current standards for PC power supplies. They require the power supply to handle the brief spikes of modern graphics cards without shutting down, and they add a 16-pin connector for the graphics card. Version 3.1 uses the 12V-2x6, a revision of the 12VHPWR connector with shorter sense pins: if the cable isn't fully seated, the card doesn't get full power, which keeps the connector from overheating.
In our catalog, every NVIDIA card from the RTX 5070 up uses that connector (as do some RTX 5060 Ti models); entry-level cards and AMD cards use 8-pin connectors. 30 of the 37 power supplies in the catalog include the native 12V-2x6 cable.
When you plug it in, push it all the way with no gap, and don't bend it right at the plug: leave a few centimeters straight before the curve.
4Protections, form factor and modular cables
- Protections: OVP and UVP (over and under voltage), OCP (over current), OPP (over power), SCP (short circuit) and OTP (over temperature). Good power supplies have all of them.
- Modular, semi-modular or fixed: with a modular unit you only plug in the cables you use, so the case stays tidier and airflow improves.
- Form factor and length: almost all are ATX; check that the length fits your case (in our catalog they measure 125 to 200 mm).
- Brand and warranty: choose a well-known maker and a long warranty, and be wary of no-name power supplies promising lots of watts for very little money.