I'm upgrading my 2020 system and want to replace an RTX 2070 Super with either an Nvidia RTX 5070 or an AMD Radeon RX 9070 XT, specifically a factory-overclocked 16GB model. The rest of the system includes an MSI MPG X570 Gaming Edge WiFi motherboard, Ryzen 7 5700X3D, NZXT Kraken X63 cooler, and 32GB of DDR4 RAM. My power supply is a Seasonic Focus GM 750W Gold. A calculator estimates roughly 600–699W for the system, so I expect it would handle the RTX 5070, but I'm less certain about the higher-draw RX 9070 XT. Will the existing 750W PSU be sufficient, or should I replace it with an 850W unit? I'd prefer to avoid unnecessary upgrades or extensive tinkering.
3 Answers
A good-quality 750W unit will probably run that combination, especially since the 5700X3D is fairly efficient. Several people use similar setups without trouble. That said, AMD's recommended PSU rating is generally around 850W for the RX 9070 XT, so 850W gives you more margin for transient spikes, aging, and future upgrades. Make sure the PSU is in good condition and that the GPU is connected with the required separate PCIe power cables rather than daisy-chaining one cable.
You can also reduce power consumption if needed. A mild GPU undervolt or a lower power limit usually costs only a small amount of performance while reducing heat and peak draw. The 5700X3D can also be tuned with a negative PBO curve offset in the BIOS, though that is optional and should be tested for stability.
Yes, the PBO curve optimizer setting is in the BIOS. Start conservatively rather than jumping straight to a large all-core negative value, then test stability.
The calculator's 600–699W estimate is a useful baseline, but it doesn't necessarily account for short power spikes from the graphics card. You can try the 750W unit first if it is relatively new and stable, but watch for crashes, black screens, or shutdowns under gaming loads. If you want a no-drama upgrade, an 850W Gold model with modern GPU power connectors would be the more comfortable option.
So it isn't an automatic failure with 750W, but 850W is the safer choice if buying a new PSU anyway.