Gigabyte: PCIe Gen5 graphics cards to require either 16-pin power cable or "3x8-pin to 16-pin" adapter - VideoCardz.com
Fasgear PCIe 5.0 GPU Power Cable Sleeved 70cm | 16pin(12+4) 12VHPWR Connector for RTX 3090 Ti 4080 4090 | Only for Corsair/Great Wall/Thermaltake Modular Power Supply
GeForce RTX 3090 Ti comes with 3 x 8-pin to PCIe 5.0 16-pin adapter
Simplifying 16 PIN (12VHPWR) PCIe5 Connector and why you need it? | PC TeK REVIEWS
Amazon.com: Fasgear PCI-e 5.0 GPU Power Cable - 70cm 16pin (12+4) 12VHPWR Male to Male Sleeved Cable with Combs, 600W PCIe 5 Power Cable for Geforce RTX 3090Ti 4070 Ti 4080 4090
PCI-E 5 Connector 16Pin 12VHPWR Set with Terminals, 5,99 €
16 Pin PCI-e (8+8) – PEXON PCS
Seasonic 12VHPWR Cable
3x8pin PCI-e to 16Pin(12+4) PCI-e 5.0 12VHPWR Connectors 16P Extension Cable for GPU 3090Ti Series - AliExpress