I'm building my first PC with an Asus Prime RX 9070 XT OC Edition, which requires three 8-pin PCIe power connectors. My Montech Century II 850W Gold power supply includes two PCIe cables, each with a second 6+2-pin connector on a pigtail. Is it safe to connect two GPU sockets using one cable and its pigtail, then connect the third socket to the second dedicated cable, leaving the second pigtail unused? I'm not planning to overclock the card and want to avoid excessive cable heat or melting issues.
3 Answers
A single pigtail can normally handle this when the cable and power supply are from a reputable manufacturer. The card’s roughly 320 W draw is well within the combined capacity of two PCIe cables, especially with one connector on the second cable. Avoid running two high-power GPU connectors from only one cable, since that places much more load on the same wiring.
Yes, that wiring is generally fine: use both PSU PCIe cables, connect two plugs from one cable and the remaining GPU socket to the other. The pigtails are provided for situations like this. Make sure every connector is fully seated and use only the modular cables supplied with that exact PSU.
It should work, but the GPU manufacturer’s warning is worth taking seriously. Keep the pigtail connection positioned so it isn’t sharply bent or under tension, make sure the plugs click firmly into place, and stop using it if you notice discoloration, a hot-plastic smell, or unusual connector heat. If a third dedicated PCIe cable is officially available for this PSU, that would be the most conservative option.
That was my main concern. Since I’m using two separate cables and don’t intend to overclock, I’ll set it up that way and check the connectors after a heavy gaming session.