What PSU do I need for a Ryzen 9 9950X?
550 W to 1200 W, depending on the graphics card beside it. With a GeForce RTX 4070 the answer is 650 W.
Where the watts go — Ryzen 9 9950X with GeForce RTX 4070
| Component | Power |
|---|---|
| Ryzen 9 9950X at its ceiling | 230 W |
| GeForce RTX 4070 board power | 200 W |
| Motherboard | 25 W |
| Memory module x2 | 6 W |
| NVMe SSD | 7 W |
| Case fan x3 | 6 W |
| Continuous draw | 474 W |
The recommendation of 650 W sits that draw at 73% of the supply's rating. The target is 80%: supplies lose capacity as they age, and a graphics card's millisecond transients have to come from somewhere.
Why the answer is a range
A Ryzen 9 9950X is sold as a 170 W processor and draws 230 W when it boosts. AMD calls the second figure PPT — Package Power Tracking — and it is the socket’s real ceiling. Sizing a supply against the 170 W on the box is short by 60 W — 35% — before the graphics card is counted at all.
With a GeForce RTX 4070 the system draws 474 W at full tilt, which calls for 650 W. Across the 34 cards below the answer ranges from 550 W to 1200 W: with this processor it is the graphics card that moves the number, not the other way round.
What the box would have told you
Size a supply against the 170 W on this processor's box and, paired with GeForce RTX 5090, you would buy 1000 W. That build draws 849 W at full tilt — 85% of the unit you just bought, with nothing left for ageing or for the card's transients. It needs 1200 W.
That is not a quirk of this pairing. On all 34 cards here, sizing from the stated TDP lands you a smaller supply than the build calls for — by as much as 200 W at the top end.
| Graphics card | Sized on TDP | Actually needed | Short by |
|---|---|---|---|
| RTX 5090 | 1000 W | 1200 W | +200 W |
| RTX 4090 | 850 W | 1000 W | +150 W |
| RTX 3090 Ti | 850 W | 1000 W | +150 W |
| Radeon RX 9070 XT | 650 W | 750 W | +100 W |
| RTX 5070 Ti | 650 W | 750 W | +100 W |
Ryzen 9 9950X with every graphics card
| Graphics card | System draw | PSU needed | Set by |
|---|---|---|---|
| GeForce RTX 5090 | 849 W | 1200 W | This build |
| GeForce RTX 4090 | 724 W | 1000 W | This build |
| GeForce RTX 3090 Ti | 724 W | 1000 W | This build |
| GeForce RTX 5080 | 634 W | 850 W | Card maker |
| Radeon RX 7900 XTX | 629 W | 800 W | Both agree |
| GeForce RTX 3090 | 624 W | 800 W | This build |
| GeForce RTX 3080 Ti | 624 W | 800 W | This build |
| GeForce RTX 3080 | 624 W | 800 W | This build |
| GeForce RTX 4080 SUPER | 594 W | 750 W | Both agree |
| GeForce RTX 4080 | 594 W | 750 W | Both agree |
| Radeon RX 7900 XT | 589 W | 750 W | Both agree |
| Radeon RX 9070 XT | 578 W | 750 W | Both agree |
| GeForce RTX 5070 Ti | 574 W | 750 W | Both agree |
| GeForce RTX 3070 Ti | 564 W | 750 W | This build |
| GeForce RTX 4070 Ti SUPER | 559 W | 700 W | Both agree |
| GeForce RTX 4070 Ti | 559 W | 700 W | Both agree |
| Radeon RX 7800 XT | 537 W | 700 W | Both agree |
| Radeon RX 7900 GRE | 534 W | 700 W | Both agree |
| GeForce RTX 5070 | 524 W | 700 W | This build |
| Radeon RX 7700 XT | 519 W | 700 W | Card maker |
| GeForce RTX 4070 SUPER | 494 W | 650 W | Both agree |
| GeForce RTX 3070 | 494 W | 650 W | Both agree |
| Radeon RX 9070 | 494 W | 650 W | Both agree |
| GeForce RTX 4070 | 474 W | 650 W | Card maker |
| GeForce RTX 3060 Ti | 474 W | 600 W | Both agree |
| GeForce RTX 5060 Ti | 454 W | 600 W | Both agree |
| GeForce RTX 3060 | 444 W | 600 W | This build |
| GeForce RTX 4060 Ti | 439 W | 550 W | Both agree |
| Radeon RX 7600 | 439 W | 550 W | Both agree |
| Radeon RX 9060 XT | 434 W | 550 W | Both agree |
| GeForce RTX 5060 | 419 W | 550 W | Both agree |
| GeForce RTX 5050 | 404 W | 550 W | Both agree |
| GeForce RTX 3050 | 404 W | 550 W | Both agree |
| GeForce RTX 4060 | 389 W | 550 W | Card maker |
Frequently asked questions
What PSU do I need for a Ryzen 9 9950X?
How many watts does a Ryzen 9 9950X actually draw?
Is the 170 W TDP the number to size a PSU against?
Does a Ryzen 9 9950X need a bigger PSU than its TDP suggests?
What happens if I size my PSU from the 170 W TDP?
A sizing estimate, not a measurement. It adds the processor's power ceiling, the graphics card's rated board power and an itemised allowance for the rest of the system, then leaves headroom so the supply is not running at its limit. Real draw depends on the board's power profile, how far the parts are overclocked, and how a particular graphics card handles transient spikes. Treat a result within 50 W of a supply's rating as a reason to choose the next size up.
Data on this page last verified .