Nvidia has no plans to drop 12-PIN PCI-e power requirement on the RTX 3070 Founders Edition Ampere GPU
The GeForce RTX 3080 Founders Edition has a 12-pin power connector, but it may be an NVIDIA-exclusive - NotebookCheck.net News
Silverstone 2x PCIe 8pin to 1x 12pin GPU power cable, black sleeved, 16AWG-550mm for SilverStone modular power supplies & NVIDIA RTX 3070/
PCI-Express Gen5 12-pin power cable looks just like NVIDIA's - VideoCardz.com
12pin PCI-E Female NVIDIA Founders Edition -
EVGA Intros PerFE 12 Individually Sleeved Cable for RTX 3090 FE and RTX 3080 FE
Amazon.com: COMeap Replaement for Dual PCIe 8 Pin Male to Mini 12 Pin NVIDIA GeForce RTX 30 Series GPU Power Adapter Cable for EVGA Seasonic Modular PSUs 25-inch(63cm) : Electronics