The original Apple graphics card power cable, the dedicated line for upgrading the graphics card, is also the dedicated line for DIY Apple graphics cards, the graphics card has an 8PIN port, G5-MACPRO are applicable.

Two mini 6P, one big standard graphics card 8P, the small head directly plugs into the dedicated graphics card auxiliary power port on the Apple motherboard, and the big head 8PIN plugs into the graphics card.
Connector 1: 1x 8-pin standard PCIe male header. Connector 2: 2x mini 6-pin male header (non-standard 6-pin male header).
Connect the PCIe video graphics card with GPU 8-pin port to the Mac motherboard with mini 6-pin port.
Compatible with Power Mac G5 and all Mac Pro models, including: (1,1), (2,1), (3,1), (4,1), (5,1) or (2006), (2007) , (2008), (2009), (2010), (2012); genuine brand new copper core, no recycled materials.
Gauge: Standard 18AWG-UL1007. Rated power: 300W.
Length (approx.): 15.7 inches (40 cm).