I'm upgrading from an RTX 2080 and am still getting familiar with the newer 12V-2x6 GPU power connectors. My Gigabyte RTX 5070 Ti includes an adapter with three female PCIe 6+2-pin inputs. My Corsair 850W power supply has two PCIe cables, each with a pigtail, giving me four male PCIe connectors in total. Would it be safe to use two cables—with one pigtail supplying two of the adapter's inputs and the other cable supplying the third—or do I need three completely separate cables? I've seen conflicting advice about whether using pigtails this way is safe.
2 Answers
The ideal arrangement is three separate PCIe cables, so each adapter plug has its own cable. If your PSU has a free PCIe socket, you can buy an additional cable specifically made for that Corsair model. If it doesn’t, replacing the PSU would be the only way to get three independent runs—but that may be unnecessary for a 5070 Ti if the existing cables and connections are in good condition.
Those limits are conservative connector specifications. Corsair’s own guidance allows some of its supplies to use two 8-pin PSU-side connections for a 600W 12V-2x6 cable, so two properly rated Corsair cables can handle more than the basic per-plug figures suggest. Check the exact PSU model’s cable compatibility before buying or reusing anything.
That setup should generally work with a quality Corsair power supply, especially for a 5070 Ti. The safest and cleanest option is still a dedicated Corsair 12V-2x6 cable rated for your exact PSU model, which avoids the adapter and pigtail arrangement. Make sure the GPU-side connector is pushed in completely and never mix modular cables from different PSU brands or models.
I was mainly concerned because I’ve read that each PCIe connector is limited to 150 watts, while the card can draw around 300 watts.