Is a 600W PSU enough for a Ryzen 7 5700X3D and RX 9070?

A good-quality 600W unit should be able to handle that combination. The manufacturer’s recommendation usually leaves room for higher-power processors and less efficient systems. The actual PSU model and build quality matter more than the wattage label alone.

600W will probably work, but 750W gives you more comfortable headroom and is the better choice if you’re buying a new PSU anyway. An 850W model is unnecessary unless you want substantial upgrade room later.

The estimated power draw leaves some margin, and similar systems have run reliably on quality 550W–600W supplies. Still, avoid relying on an unknown or low-end unit, especially if the PSU is old. Check the exact model, efficiency rating, protections, and whether it has the appropriate GPU power connectors.