What PSU do you need for a AMD Radeon RX 6400?
The AMD Radeon RX 6400 has a vendor-published board power (TGP/TBP) of about 53 W. Sizing a power supply from that figure and a typical companion system (a 125 W-class CPU plus standard ATX accessories, ~242 W), here is what we recommend.
Recommendations are planning estimates, not electrical or purchasing advice. The hardware figures behind them are vendor-published; your exact board-partner model and build can still differ.
Recommended (comfortable)
450 W
Standard headroom for transient spikes and a little future room.
Minimum
450 W
Smallest quality PSU tier we would pair with this card in a typical build.
GPU board power
53 W
Vendor TGP/TBP — a conservative ceiling, not typical gaming draw.
Vendor-recommended PSU
350 W
The wattage the GPU vendor lists — deliberately conservative.
Power connector
No external power connector (slot-powered). This card is powered entirely through the PCIe slot — no separate PSU cable needed. See connector & ATX 3.x details →
Why 450 W for this card
The AMD Radeon RX 6400's draw is not flat. Brief spikes above the rated board power are normal, and they are short enough that a wall meter never shows them — but a power supply sitting close to its limit can trip on one. That is what the headroom in these figures is for: 53 W is the sustained ceiling, not the worst instant. This card draws through the PCIe slot alone, so there is no GPU cable in the transient path at all. At 53 W a quality unit of the recommended wattage handles transients without drama; an ATX 3.x supply adds margin but is not essential. We do not publish a spike figure for the AMD Radeon RX 6400 because the manufacturer does not publish one.
On the recommended 450 W supply, a Ryzen 7 9800X3D paired with the AMD Radeon RX 6400 draws roughly 332 W under load — about 74% of the unit's rating. The 80 PLUS programme certifies efficiency at 20%, 50% and 100% load, and units are typically at their best around the middle of that range, so this sits in a sensible place: enough margin for transients without paying for capacity that never gets used.
The manufacturer recommends 350 W; our comfortable figure is 450 W, 100 W higher. Vendor recommendations assume a mainstream companion system, while our figure adds standard headroom on top of a typical build. 350 W is not wrong — but if you are running a power-hungry CPU or want the supply loafing rather than working, the larger unit is the safer buy.
Pairing this card with different CPUs
The CPU does change the answer here. With a Ryzen 5 7600 this build sits on a 450 W supply, but moving to a Core i9-14900K (253 W peak) pushes the estimate to 550 W. If you are pairing this GPU with a high-power CPU, budget for the larger unit.
| CPU | CPU peak | System load | Recommended PSU |
|---|---|---|---|
| Ryzen 5 7600 | 88 W | 258 W | 450 W |
| Ryzen 7 9800X3D | 162 W | 332 W | 450 W |
| Core i9-14900K | 253 W | 423 W | 550 W |
Other popular choices map onto this table rather than changing it: the Ryzen 7 7800X3D has the same 162 W peak as the Ryzen 7 9800X3D, so that row applies to it unchanged; a Core i5-14600K (181 W peak) lands on the same 450 W tier as the Ryzen 5 7600; a Ryzen 9 9950X (230 W peak) lands on the same 550 W tier as the Core i9-14900K.
Assumes an ATX board, 2 RAM sticks, 1 SSD, 3 fans and a USB allowance, at the standard headroom profile. Change any of it in the calculator.
Cabling this card
This card takes all its power through the PCIe slot, so there is no GPU power cable to get wrong — any supply that meets the wattage above will do.
Want a number for your exact CPU and parts? Open the full PSU Calculator with this GPU pre-selected →
The standards behind these numbers
- How much PSU headroom do you actually need?
Why the recommendation above sits above the 53 W board power rather than on it.
Worth knowing
Slot-powered only, 53W typical board power; no external power connector on any known partner card.
Board-power source: AMD official specification; multi-agent web verification 2026-07-15. Last updated: 2026-07-15.
Frequently asked questions
What size PSU do I need for a AMD Radeon RX 6400?
For a typical build that pairs the AMD Radeon RX 6400 (about 53 W board power) with a 125 W-class CPU and standard accessories, plan for at least a 450 W power supply. A 450 W unit gives comfortable headroom for transient spikes and future upgrades. These are estimates — verify against your exact parts.
How much power does the AMD Radeon RX 6400 draw?
Its vendor-published board power (TGP/TBP) is about 53 W. That is a conservative ceiling used for PSU sizing, not the typical draw you would see while gaming.
Is a 350 W PSU enough for a AMD Radeon RX 6400?
AMD Radeon RX 6400's manufacturer lists a 350 W PSU recommendation. That figure is deliberately conservative to cover weaker units and power-hungry CPUs, so a quality 350 W supply is a safe choice. Our own estimate for a typical build is a 450 W minimum and 450 W for comfort.
Does the CPU change what PSU the AMD Radeon RX 6400 needs?
Yes. With a Ryzen 5 7600 the estimate is 450 W, while a Core i9-14900K (253 W peak) takes it to 550 W.
Why does this differ from AMD Radeon RX 6400's official PSU recommendation?
The manufacturer lists 350 W and our comfortable figure is 450 W. Vendor guidance assumes a mainstream companion system; ours adds standard headroom to a typical build. Both are shown on this page so you can judge.