There's no such connection that you describe and you need to use each cable for it's specific purpose.
If you look up my power suply the Evga supernova 550w modular gold efficiency there is six pins labled as sata and six pins labled as pci-e and I was wondering if the sata could be used for the gpu
They are for storage drives and optical drives and sometimes other things , mostly for HDD and SSD.
Yeah sorry got a bit confused I know what sata cables are for and I I'm fine with all that I was just wondering if that was a posiblity and I'm not sure if you really knew what I was talking a bout as well but thanks for your feedback nonetheless