I have an older EVGA SuperNOVA 650 G3 power supply (model 220-G3-0650-Y1) and am considering upgrading to a Radeon RX 9070 XT or GeForce RTX 5070 Ti. These newer graphics cards use a 16-pin power connector, and the included adapter appears to convert three 8-pin PCIe plugs into the 16-pin connector. My PSU only seems to have two PCIe cable connections available. Can I safely use this adapter with my current power supply, or should I replace the PSU first?
4 Answers
The bigger concern is the 650W capacity, not just the connector count. Modern GPUs can have short power spikes, and AMD commonly recommends a higher-wattage supply for the RX 9070 XT. A quality 750W–850W PSU with native, appropriate connectors would give you more headroom and avoid relying on adapters or daisy-chained leads.
I would replace the PSU at the same time as the GPU. Use a current, reputable model with enough wattage and the correct native cable for the graphics card. That removes uncertainty around adapter loading, cable configuration, and transient spikes.
Many standard RX 9070 XT models use two 8-pin connectors, while factory-overclocked versions such as some premium designs use three. Choosing a two-connector model would make compatibility with your current cabling simpler.
That EVGA model has three PCIe connectors distributed across its two modular cables, so it may provide enough plugs for a three-8-pin adapter. Still, check the PSU manual and use the original PCIe cables—not CPU/EPS cables—and make sure every connector is fully seated.
I thought daisy-chaining PCIe connectors was generally discouraged. Is it actually safe here, or should each plug come from a separate cable?
Even if the existing cables technically fit, replacing the PSU seems like the safer choice when the graphics card is such a large part of the system cost.