powering my GTX280

[biff]

The GTX 280 needs a 6pin + 8pin, my psu has 2x6pin cords. In doing research on it it appears that the 6pin and 8 pin are identical (pin location & header shape) with the exception of two additional grounds for the 8pin - so the 6pin should just plug in and supply power just fine. I did find people saying that it will not work because the 6pin standard was only meant for 74W and the 8pin for 150W but my PSU clearly states that each PCIE power connector comes from a different rail each capable of 18A (216W) - so the available power is there too. Some people mentioned that the card (talking about ATI) would work with the 6 pin but would detect the two missing grounds and disable over clocking features. This sounds a bit bogus to me as I'd figure they'd all be soldered onto the same ground plane on the PCB.

Any thoughts?

[enaberif]

Originally Posted by biff

The GTX 280 needs a 6pin + 8pin, my psu has 2x6pin cords. In doing research on it it appears that the 6pin and 8 pin are identical (pin location & header shape) with the exception of two additional grounds for the 8pin - so the 6pin should just plug in and supply power just fine. I did find people saying that it will not work because the 6pin standard was only meant for 74W and the 8pin for 150W but my PSU clearly states that each PCIE power connector comes from a different rail each capable of 18A (216W) - so the available power is there too. Some people mentioned that the card (talking about ATI) would work with the 6 pin but would detect the two missing grounds and disable over clocking features. This sounds a bit bogus to me as I'd figure they'd all be soldered onto the same ground plane on the PCB.

Any thoughts?

With the ATI cards if you don't plug in the 8 pin your right (or what I've heard) and you lose the "Overdrive" part for the cards.

With nvidia its different you need both the 6 and 8 plugged in or the card won't power up.

This comes down to 3 ways:
1) Adapter
2) Create your own grounds
3) New PSU

Personally if you go for #1 you might as well go for #3; #2 I've heard people have had no issues with.

[Chilly]

enaberif, You are correct, ATi cards will work properly, but with the "loss" of overdrive settings if you use a 6pin instead of an 8pin.

As for nVidia cards, your best bet would be to get an adaptor or create your own. Biff, I've got a bunch of 6-8pin adaptors laying around if you'd like some. PM me if you'd like them!

[biff]

Just found a few other tidbits of info. The extra two grounds are only for sensing what connector is plugged in to differentiate to two different wattage standards for the purpose of imposing restrictions (like the ATI example). So it appears just modifying the plug to add the two extra pins like a 6+2 connector should work just fine since I know the 6pin plug I do have is capable of the full wattage req'd.

[edit]Thanks Chilly, If I can find a connector off an old PSU to canibalize for the extra two pins then it'll be a few minute fix. If not then I may be in touch.[/edit]

[biff]

I stole the connector off the 8pin adapter that came with the card, pulled the pins out and put in the pins from the existing 6pin from my PSU, added in the extra two grounds and it works perfectly.