# The molex connector helps prevent physical cable damage and possible motherboard wear from running a dual-GPU video card through an extender cable
I don't know if I need a molex conector. Does this means it is better but not necessary in any case?
Take a look at this: http://blog.zorinaq.com/?e=44
If all you've got is one card, you don't need the molex connector, as the cable itself can handle the current that the card draws from the motherboard. The problem is when you're running multiple cards, the power drawn through the motherboard all adds up, and can potentially melt something.
I don't know the exact point at which you need the molex connector. I went with it for the single 5970 on my 5-card rig. Maybe I could have gotten away with not using it, but I didn't want to take the chance.