2 EPS connectors on X570 motherboard and how to power them

My motherboard has (8+8)-pin EPS connectors. According to this video at 04:21 ([ame]

[/ame]), the second one feeds PCI-E slots. If it is, I was wondering if it will have any effect on my single GPU and whether it’s necessary to plug that second connector at all. However, MSI’s support asserts that both connectors are for CPU.

 

I own CableMod C-Series ModMesh Cable Kit for Corsair RMi / RMx / RM (https://cablemod.com/product/cablemod-c-series-rmi-rmx-modmesh-cable-kit-carbon/) that has two (4+4)-pin EPS cables because the kit is meant for PSU of any wattage from RMi/RMx line. This cable kit is a direct replacement for stock cables and all appropriate cables have capacitors on them.

 

My Corsair RM650i multi-rail PSU has 3 connectors on modular panel designated as 6+2 PCI-E & 4+4 CPU. Can any of them be used for connecting to EPS on motherboard or PCI-E on graphics card interchangeably? If yes, I was wondering if I can run just one CableMod ((6+2)+(6+2))-pin PCI-E cable to my graphics card and two CableMod (4+4)-pin EPS cables to (8+8)-pin EPS connectors on the motherboard? Will my graphics card have adequate power especially when overclocking from one PCI-E connector on modular panel and one cable? Will PSU be able to give adequate power to two 8-pin EPS connectors on the motherboard from two connectors on modular panel using two EPS cables? In this suggested configuration, should I keep PSU working in multi-rail mode or switch to a single-rail?

 

Thank you in advance!