I'm currently looking for a new graphics card to replace my ageing ATI 1950 gt. I have been looking at the ATI HD 5770 1GB and the HD 5830 1GB cards. The 5770 requires 1 6pin power connector which is fine, however the 5830 requires 2 6pin power connectors. My PSU (Arctic Power 700w) only has 1 6pin connecter and only 3 molex connections which are all being used. I have been looking at getting a bunch of molex splitters ( http://www.scan.co.uk/products/Power-Splitter-Cable-Mol...(RB-511) ) to solve the problem. However, is this wise? I'm not sure if it would cause power problems dividing up the power supply to so many molex connectors.
I have read a couple other threads on the forums about this same problem but these threads were a couple years old and I'm still a little unsure.
What you want to look at is what those molex connectors are being used for. If they're being used to power your case fans, I don't think you'll have too much of an issue due to the very low amperage and wattage requirements.
If they're being used to power other high power required devices, then you may have problems. I wouldn't ever recommend it either way, but I imagine it could be done since you have a decent PSU.
I do have one of the case fans running off of a molex which I could split. The other 2 devices are the hard drive and optical drive, I think I could split the optical drive since I hardly ever use it (most of my games I have are on steam) but if that isn't recommended then i'll have to stick with the 5770 card.