i connect my gpu's directly to power using the pci-e connections located directly on my gpu's and this seemed to work ok for a while....

but now I'm expanding to 5 GPU's and I've run out of pci-e cables from my psu...  should i be running power to my risers (molex) instead of directly to my cards? 

are they equivalent to each other?  i.e. can i power some of my risers using molex cable and power the other ones by hooking power up directly to the gpus?

thanks in advance!