New build --- 8/6 Pin Pci Express power confusion

I've recently been building a new system and it was going swimmingly until it came to power my HD 5850. The powercool PSU I got was advertised as having 6 pin Pcie connectors (Of which the 5850 needs two), however, it came with some wierd hybrid 6+2/8 cables. Essentially one end was an 8 pin, which I presume plugs into the PSU, and the other end can convert to a 6 pin from a 6+2. The question is would supplying a 6 pin socket through an 8 pin power outlet damage the graphics card? :heink:
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  1. The extra two couldn't be used. Also they're keyed so you can't put the individual ones in wrong. So it should be fine, the only problem I can think of is that maybe the two extra pins would be physically in the way of something on the graphics card itself.
  2. Thanks for the reply, but what I'm worried about is how the PSU is supplying the power out of sockets labelled "8 pin pcie". I have two "6 pin pcie" sockets, but as mentioned the cable only splits to give a 6 pin setup at one end, forcing me to use the 8 pin power outputs.
  3. mr pi said:
    The question is would supplying a 6 pin socket through an 8 pin power outlet damage the graphics card? :heink:

    No. If you look at the 6 and 8 pin PCIe connectors, they both have 3 hot wires (the yellow 12 volt leads). The 2 wires of the "6+2" connectors are both extra ground leads. So either way, you only have 3 wires carrying power into the video card.

    Speaking as someone who has been in electronics for more than 40 years (starting as a hobbyist), I just do not see how adding two ground wires is going to double the current carrying capacity of three hot wires.
  4. Thanks for the help, gonna go ahead and turn it on now. Guess I was just fretting over frying my shiny new HD 5850 (upgrading from a 8600gt in my old system).
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