Question PCI e cable Corsair Rm750 Or rm850 and Seasonic snow

[CG5004]

This will be my first time build On the pci e cable on consair it got two connectors on one cable To Connect to gpu like a rx580 sapphire nitro has it got enough power to power the card ? Also if I decide to go 1660 ti it only got one 8 pin connector do I use 2 Connect cable but only just plugging in one 8 pin leaving the other out ? Or is it best to buy just PCI e cables with just single end of 8 pin ? For both of the gpu ? I do not If u can buy them Separate. Plus rm750 or rm850 or Seasonic prime snow silent 650 80 plus platinum

Am looking at 2600x ryzen ,msi tomahawk max ,Corsair ram 3000mhz already got cooler master Mc600p case and pny 480gb ssd and window pro it just Getting the right psu that worry me.

 

[ViktorHX]

There should be enough power for the GPU, cause 1 8pin or the other is out and the second isn't connected doesn't affect anything. I have 6+2pin coming out of my PSU, and only the 6pin goes in and the 2pin is out and not connected. Most of PSUs that have more then 550w will have enough power for the system you are looking at.