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Quote:

Originally Posted by KoolGuy View Post
I know but some cables only provide 2 12v.
Oh sorry, I misread your original question.

I don't know if there is something it specifically powers as the card is obviously drawing from the PCI-E slot itself as well.

My theory is that if it's an adapter, it's most likely designed for the power requirement of whichever card it came in and simply did not require the extra +12v wire.

As for power supplies, I would assume same idea. Lower end would only have two since they aren't expecting high drawing GPUs.

I can't find any information on it that's actually from a reliable source, best I found was someone else asking on another forum and all they said was "Pin 2 by spec is not connected, although some PSU manufacturers do add a 12V line there" so that doesn't really help.
 

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Discussion Starter #5
Quote:

Originally Posted by Peroxide View Post
Oh sorry, I misread your original question.

I don't know if there is something it specifically powers as the card is obviously drawing from the PCI-E slot itself as well.

My theory is that if it's an adapter, it's most likely designed for the power requirement of whichever card it came in and simply did not require the extra +12v wire.

As for power supplies, I would assume same idea. Lower end would only have two since they aren't expecting high drawing GPUs.

I can't find any information on it that's actually from a reliable source, best I found was someone else asking on another forum and all they said was "Pin 2 by spec is not connected, although some PSU manufacturers do add a 12V line there" so that doesn't really help.

Yea same here..

I made assumption tho..

The cable is Unrated at 75W. Meaning that is a Video card manufacture wanted more then 75W they would have to use another connector.
Hence the 8 pin connector with a capacity of 150W.

How ever this is only a assumption..
 

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I only see Ping 2 missing with adaptors.
I really have no idea what difference it really makes but I'm sure there is when the extra 12v is required (over-volt maybe?)
Yet, I have no problems running a 4890 on an Antec 430W with 1 PCIe from the PSU and one from the adaptor and my 8800GTS PhysX is running on an adaptor.

Still, I hope someone might give us the peace of mind with an answer.
 

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Quote:

Originally Posted by andynolife View Post
I really have no idea what difference it really makes but I'm sure there is when the extra 12v is required (over-volt maybe?)
This is making more sense to me as I am reading.

http://www.playtool.com/pages/psucon...tml#pciexpress

Take this site for what you want, but it states that PCI-E power specification were not made public and eventually leaked which may be why it's somewhat hard to find information about the 2/3 +12v variation. They state the 6-pin PCI-E power connector should theoretically be able to output more than 75w.

Quote:
I have no idea why the wattage is rated so low because the specifications from Molex clearly allow substantially more power. Part of the reason may be that pin 2 (listed above as a 12 volt line) may be listed as not connected in the specification.
This along with the fact that the 8-pin PCI-E power connector still only has 3 +12v lines but can output 150w makes me believe that the bolded text above could certainly be true.

If it's true that the 75w specification is only using 2 +12v then the 3rd very well could have just been extra headroom like andynolife stated above.
 

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Discussion Starter #9
Quote:

Originally Posted by Peroxide View Post
This is making more sense to me as I am reading.

http://www.playtool.com/pages/psucon...tml#pciexpress

Take this site for what you want, but it states that PCI-E power specification were not made public and eventually leaked which may be why it's somewhat hard to find information about the 2/3 +12v variation. They state the 6-pin PCI-E power connector should theoretically be able to output more than 75w.

This along with the fact that the 8-pin PCI-E power connector still only has 3 +12v lines but can output 150w makes me believe that the bolded text above could certainly be true.

If it's true that the 75w specification is only using 2 +12v then the 3rd very well could have just been extra headroom like andynolife stated above.
I was actually reading from that site earlier how ever it sucks that we cant get any specifications
 
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