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PSU PCI-e Power vs. Supplied PCI-e Power


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#1
FalloutYear

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Well, I just noticed that my supplied PCI-e power is a 6 pin, but only has 3 wires. So, it looks like this;

[ ][.][.]
[ ][ ][.]

Currently, I'm using my PSU's supplied PCI-e connecters which is 6 pin with 6 wires. It looks like this;

[.][.][.]
[.][.][.]


Is there a difference? Should I switch to the supplied PCI-e power cable?
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#2
Jack123

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01 FalloutYear 6 pin PCI Express Power
16th April 2006

I just noticed that my supplied PCI-e power is a 6 pin, but only has 3 wires
I'm using my PSU's supplied PCI-e connecters which is 6 pin with 6 wires
Is there a difference? Should I switch to the supplied PCI-e power cable


Many new PCI-Express video cards use this 6-pin connector as additional source of power, because the PCI-E bus is limited to 150W power draw max. Some of these Video Cards will draw 15 amps off the 12 Volt Power – which is 180 watts, which would melt/burn the Motherboard PCI Connector-

So not only a is larger Power Rated PSU is required, but also larger Power Rated Connectors are required. Another factor to be considered is the Voltage drop of the 12 Volt line. A line resistance of 0.1 Ohms at 12 Volt would yield a 1.2 Volt drop in the 12 Volt Line which might be Ok – but if the Line Resistance was 0.3 Ohms, this would yield 3.6 Volts – [30% drop].

This would cause significant degrading of performance of the Video Card. Adding the additional parallel power wires would reduce this line drop & improve performance. The Wired connector from the PSU would have better Voltage Regulation – Only if the Video Card has all 6 pins wired – – If not, then you should pick the one with the Largest Wire Diameter – Note - [If not all of the pins are used - this could cause Video Stuttering due to Poor Voltage Regulation]

You can determine – Quality & Performance – by observing the – Quality of Integration Engineering – Wiring is a Critical Component -

Jack123

Edited by Jack123, 16 April 2006 - 06:07 PM.

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#3
jrm20

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Well, I just noticed that my supplied PCI-e power is a 6 pin, but only has 3 wires. So, it looks like this;

[ ][.][.]
[ ][ ][.]

Currently, I'm using my PSU's supplied PCI-e connecters which is 6 pin with 6 wires. It looks like this;

[.][.][.]
[.][.][.]
Is there a difference? Should I switch to the supplied PCI-e power cable?



Look at this Y adapter included with this video card.....


http://www.newegg.co...s...rd - Retail

Do you see that it has 2 molex connectors with 3 wires each, then all 6 wires going into the pci express connector?

Well if you used this type of connector you need to hook up both of those molex connectors to the powersupply on the same rail and that is all there is to it...

Thats the only way I can explain this..
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#4
Jack123

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02 – FalloutYear – [6 pin PCI Express Power Connector]
17th April 2006

Do you see that it has 2 molex connectors with 3 wires each, then all 6 wires going into the pci express connector?


Yes this is an – Adapter Connector – that can be used with an adequate PSU that does not have the 6-pin PCI Express Video Connector – The usage of the 6 wires is to reduce Line Resistance & Contact Resistance, which becomes significant with high current draw on the +12V Line.

This high current is not necessarily constant – but is Peak Current and has to React Instantly to the speed of the Video Circuitry demand for current to function properly to its specification. If this Peak Current Draw is delayed/muted when demanded, then you will clearly see the Degrading Video Results.

Who gets blamed? – The Video Card – or The Power Supply. But, I am saying – No – It is the PC/PSU Wiring. It is not just a matter of getting a connection – but getting a Quality Connection with a quality ground/return and proper EMI shielding.

My concern on this issue was that the Video Card Manufacturer did not recognize this need/requirement to supply an adequate Power Adapter Connector [??] which makes me question – Design Quality of the Video Card – and does the Video Card use all 6-pins to supply power to the board [??] – And how well is the power distributed throughout the Card [??]

I am requesting FalloutYear to visually inspect the Video Card to determine if there are track connections to all 6 pins on the Card and if the card is multilayered with a Power Plane & Ground Plane sandwiched between the outer layers. Give me the Model & Manufacturer P/N for me to research.

Jack123

Edited by Jack123, 19 April 2006 - 05:34 AM.

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#5
FalloutYear

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Sorry and thanks for the replies! Totally forgot about this topic! Anyways, upon inspection I noticed that all of the 6 pins in the plug on my graphics card all go into my card (6 metal wires going into the gcard PCB). Here is the graphics card I have; http://www.newegg.co...N82E16814102007.
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#6
jrm20

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Sorry and thanks for the replies! Totally forgot about this topic! Anyways, upon inspection I noticed that all of the 6 pins in the plug on my graphics card all go into my card (6 metal wires going into the gcard PCB). Here is the graphics card I have; http://www.newegg.co...N82E16814102007.




Hard to tell.. Does your Y adapter included with the video card have just 3 wires going to the 6 pin pci express connector?
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#7
FalloutYear

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Yeah, just 3. 3 have them, and the other 3 are empty.
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#8
jrm20

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Yeah, just 3. 3 have them, and the other 3 are empty.



ok, all you do then is use the included Y adapter and only hook your power supply up to one of the molex connectors and thats it, ulness the instructions say otherwise..

Edited by jrm20, 19 April 2006 - 07:35 AM.

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#9
FalloutYear

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ok, all you do then is use the included Y adapter and only hook your power supply up to one of the molex connectors and thats it, ulness the instructions say otherwise..


I was talking about the included adapter. It's not a Y either. The supplied has only 3 wires going into the PCI-e end. My graphics card has all 6 out of 6 which go into the PCB. The one on my PSU has 6 wires going into the PCI-e power and it's working fine.
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