Hey so I wanted to buy an ATI Radeon 5850 which requires 2x6pin connectors to power the card, however, my power supply only has one 6-pin connector. Does this card REQUIRE 2 of the 6pin pci connectors to run, or as long as there is enough power going through the single connector it will still run?
Yes the card would require both 6 pin connectors, your PSU isn't designed to power such cards, hence the single 6 pin connector.
AMD recommend a PSU with atleast 500W, although your PSU is of good quality it just doesnt have the power for a HD5850 (+ The rest of your PC)
I'm pretty sure a 5850 is 151 watts. The PCI express slot supplies 75 watts, and a 6 pin PCI express connector supplies 75 watts. A better choice for your situation may be a 6850 which should be similarly priced with similar performance but uses about 30 watts less and only requires one PCI express 6 pin.