What PSU do you need for the RX 7800 XT?
With a 120 W CPU such as the Ryzen 7 9800X3D: 750 W is the safe choice, and a good-quality 650 W unit also covers the card's measured draw.
With a 65 W CPU, 750 W (650 W good-quality). With a 253 W CPU, 750 W.
Measured card power, not rated power: 250 W average while gaming, 318 W highest 20 ms spike.
Is my power supply enough? 450–1600 W
Each cell is the sustained gaming load as a share of the label. ✓ Safe: the load fits, the card's measured spikes stay under the label, and the size meets the higher published recommendation (700 W). ✓ Good unit: the measured draw fits, but the size is below 700 W — fine with a well-reviewed unit, not with a no-name one. ✗: not recommended — the steady load is over 80% of the label, a spike passes the label, or the size is below 700 W without meeting the good-unit bar.
| PSU | 65 W CPU e.g. Ryzen 7 9700X | 120 W CPU e.g. Ryzen 7 9800X3D | 253 W CPU e.g. Core i7-13700K |
|---|---|---|---|
| 450 W | ✗ 87% | ✗ 99% | ✗ 128% |
| 550 W | ✗ 71% | ✗ 81% | ✗ 105% |
| 650 W | ✓ Good unit 60% | ✓ Good unit 68% | ✗ 89% |
| 750 W | ✓ Safe 52% | ✓ Safe 59% | ✓ Safe 77% |
| 850 W | ✓ Safe 46% | ✓ Safe 52% | ✓ Safe 68% |
| 1000 W | ✓ Safe 39% | ✓ Safe 44% | ✓ Safe 58% |
| 1200 W | ✓ Safe 32% | ✓ Safe 37% | ✓ Safe 48% |
| 1600 W | ✓ Safe 24% | ✓ Safe 28% | ✓ Safe 36% |
Sustained load = card's measured gaming draw + CPU at its TDP (Intel 12th gen and later: maximum turbo power; games usually draw less, so this errs high) + 75 W for board, memory, drives and fans: 65 W CPU 390 W · 120 W CPU 445 W · 253 W CPU 578 W.
Measured power draw
| Gaming average | 250 W |
|---|---|
| Highest 20 ms spike | 318 W |
| Rated board power | 263 W (AMD) |
| Card measured | AMD Radeon RX 7800 XT |
Measurements are from TechPowerUp's review of this card, which records card-only power with dedicated equipment. TechPowerUp's test method has changed over the years, and newer test runs of the same card can read higher — one more reason the safe choice never goes below the published recommendations.
Why PSU recommendations disagree
- AMD: 700 W (spec page). The maker's figure has to cover any CPU and any power supply.
- TechPowerUp: 650 W minimum, sized from the card's measured draw.
- Most online calculators add up rated power (TDP) for every part and then add a margin. Rated power is not what a card or CPU actually draws in games, which is why their answers can differ by 100 W or more.
- This page: the safe choice never goes below 700 W, the higher of the published figures. The good-unit size uses the measured draw and never goes below TechPowerUp's minimum. See the methodology.
Connectors
Expect two 8-pin PCIe connectors or a single 12V-2x6 depending on the model. Most 650–850 W units from the last five years have both.
When to step up a size
Overclocking, a factory-overclocked card, more than four drives or a lot of fans and RGB each add tens of watts. If two or more apply, take the next size up. Check your exact card's spec sheet too — some board partners list a higher minimum.
Try your exact CPU in the PSU calculator · Best CPU for the RX 7800 XT