Sizing

How many watts do I need?

Your graphics card decides most of the answer. Here is how to size a power supply properly, with tables, worked examples and the mistakes to avoid.

Short answer: most gaming PCs need between 650W and 850W. An RTX 5090 needs 1000W or more. Find your graphics card below, add headroom if you have a power-hungry processor, then round up.

Quick reference: RTX 50 series

These are the power figures for Nvidia's current cards, as listed in PC Gamer's spec table. "Recommended size" is the whole-system power supply size for a typical build.

Graphics cardCard powerRecommended size
RTX 5090575W1000W
RTX 5080360W850W
RTX 5070 Ti300W750W
RTX 5070250W650W
RTX 5060 Ti600W (MSI)
RTX 5060550W (MSI)

RTX 5090 to 5070 from PC Gamer's spec table. RTX 5060 Ti and 5060 from MSI's recommendations for standard gaming builds.

AMD cards

AMD figures vary more, because partner cards are often overclocked. MSI recommends 750W to 850W for an RX 9070 XT build. Some factory-overclocked models ask for more: Tom's Hardware reported that the RX 9070 XT Red Devil's box recommends 900W, while AMD's Frank Azor confirmed other models would need less. Always check the box or product page for your exact card.

For older AMD cards, Tom's Hardware lists the RX 7900 XTX at 355W board power with an 800W recommendation.

Older Nvidia cards

MSI publishes ranges for previous generations. The lower figure is for a mid-range processor, the higher one for a top processor with overclocking.

Graphics cardMSI range
RTX 4090850W to 1300W
RTX 4080 / 4080 Super750W to 1250W
RTX 4070 Ti / Ti Super750W to 1000W
RTX 4070 / 4070 Super650W to 850W
RTX 4060 Ti550W to 750W
RTX 4060550W to 650W
RTX 3090750W to 1000W
RTX 3080 / 3080 Ti750W to 1000W
RTX 3070 / 3070 Ti650W to 850W
RTX 3060 / 3060 Ti550W to 750W

Then account for your processor

The processor is the second biggest power user. Gaming-focused chips are fairly modest, but top multi-core chips can draw a lot under heavy work. Tom's Hardware lists the Ryzen 9 9950X at up to 230W and the Core Ultra 9 285K at up to 250W under maximum boost.

The card recommendations above already include a typical processor. If you have a top chip like these, or you plan to overclock, add about 100W.

Why spikes matter more than averages

Modern graphics cards don't draw a steady amount. They spike for fractions of a second, well above their rating. In MSI's testing, a whole system with an RX 9070 XT averaged around 455W to 501W in games, but peaked at 864W to 1029W.

A weak or older power supply can see those spikes as a fault and shut down, which looks like a random crash while gaming. ATX 3.0 and 3.1 power supplies are designed to handle short spikes like these, which is why every unit on my list meets one of those standards.

Weak power supply trips hereAverage gaming drawShort spikes go far above the average
Illustration, not measured data. In MSI's RX 9070 XT tests, system peaks reached about double the average.

Why a little bigger is better

What you don't want is a unit so large that your PC idles at a tiny fraction of its rating. Efficiency drops at very light loads, and you pay more for capacity you won't use.

Worked examples

BuildCard saysAdjustBuy
Ryzen 5 + RTX 5060550WNone needed650W gives comfortable headroom
Ryzen 7 9800X3D + RTX 5070 Ti750WNone needed750W
Core Ultra 9 285K + RTX 50901000WAdd 100W for the processor1200W
0W200W400W600W850WExample: RTX 5080 build on an 850W power supplyGraphics card ~360WCPU ~120WRestHeadroom ~295W
Typical figures for illustration. The headroom covers short spikes and keeps the unit near its efficient middle range.

Mistakes to avoid

Three steps to your number

  1. Find your graphics card in the tables above.
  2. Add about 100W for a top processor or overclocking.
  3. Round up to the next common size: 650W, 750W, 850W, 1000W or 1200W.

Prefer to plug in your parts? Use the calculator on the homepage. For a card-by-card list with picks, see the best power supply for your graphics card.

My picks at each popular size

Questions

Is 750W enough for an RTX 5070 Ti?

Yes for a typical build: 750W is the recommended size. Go to 850W if you have a top processor or plan to overclock.

Is 850W enough for an RTX 5090?

No. The recommended size is 1000W, and I would go to 1200W with a top processor.

Is 650W enough for an RTX 5070?

Yes for a typical build. 650W is the recommended size.

Can a power supply be too big?

It won't harm anything. Efficiency drops a little at very light loads and you pay more, but a modest step up is a good idea.

Why does my PC shut down when gaming?

It can be the power supply failing to handle the graphics card's short power spikes. See the guide to the signs of a failing power supply.

Do I need to add up every component?

No. Start from the graphics card recommendation, which already includes a typical system, then add headroom for a top processor.

Sources

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