When I replaced the motherboard, I made sure that all of the Front Panel Connectors were in the right place. I have 1 PCI Express connected to my GPU because that's all it has. Both of my SATA cables are connected to the HDD & Optical Drive. Both are powered to the PSU. I wish that was the case.
My fans have their own designated string connected to the PSU. My PSU is modular & 700W. More than enough power.