[SOLVED] Alienware RX 51 R3 Swap Power Cable To GPU

ExaltedOne

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Apr 14, 2016
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I recently bought an Alienware RX 51 R3 with an upgraded graphics card that requires an 8 pin power connector but there is only a dual 6 pin cable from the motherboard to the gpu with only one 6 pin plugged in. To avoid the wait time on an adapter I was going to use a cable from a modular power supply that converts an 8 pin from the power supply to two 6 pins. Would it be possible to use the cable backwards in the RX 51R3 with one of the 6 pins connected to the motherboard and the 8 pin in the graphics card? I’ve read that it’s bad to swap modular cables but the RX 51 R3 case doesn’t use a regular power supply. In my head I can’t see why it wouldn’t work but don’t want to risk frying anything
 
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I would not do that as the 2x distinct power connectors could be on two different power rails and connecting them together would create a short in the power supply.

What I would recommend is an HP part number N1G35AA aka 721859-001. It is a factory 6-pin to 8-pin converter designed for use in HP's workstations and isn't some cheap piece of junk (unless it's a chinese fake). You can find them used on ebay regularly:
https://www.ebay.com/itm/HP-721859-...f0d0c5b11:g:~zUAAOSw69td5zq2&autorefresh=true

I actually have a whole box of these, so PM me if you want one as I can sell you one much cheaper than ebay.
It's highly unlikely that any of the pinouts are the same, and unless you can 100% verify that they ARE by way of an accurate pinout diagram for all cables and hardware involved, it's the worst possible idea you could ever have. We get about four or five people per week here who show up because they've used modular cables from some other model of PSU with what they have installed and either fry just the PSU or a bunch of crap. I'd highly recommend you don't do it.

Furthermore, there should NEVER be any power cables that go from the motherboard to the graphics card. Power cables should ALWAYS go from the power supply to the graphics card, or from the power supply to the motherboard, but never from the motherboard to the graphics card. Something is either wrong, or already adapted, improperly. Pictures are often helpful when trying to explain extraterrestrial configurations. :)

 
I would not do that as the 2x distinct power connectors could be on two different power rails and connecting them together would create a short in the power supply.

What I would recommend is an HP part number N1G35AA aka 721859-001. It is a factory 6-pin to 8-pin converter designed for use in HP's workstations and isn't some cheap piece of junk (unless it's a chinese fake). You can find them used on ebay regularly:
https://www.ebay.com/itm/HP-721859-...f0d0c5b11:g:~zUAAOSw69td5zq2&autorefresh=true

I actually have a whole box of these, so PM me if you want one as I can sell you one much cheaper than ebay.
 
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ExaltedOne

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Apr 14, 2016
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That.

But I assume those connect to dual six pin connectors coming from the PSU, not the motherboard, right? If they come from the motherboard, then that is a type of configuration that I've never seen or heard of before.
so the power supply in this case is like a laptop and is supplied from the box on the cable that plugs into the little green board you see in the top left of the picture. That runs a cable to a 6 pin on the motherboard to supply power to everything. There is another 6 pin on the motherboard that runs a cable that splits to 2 6pins for the graphics card. I scrapped any ideas i had and called around for an adaptor and found a local computer shop that doesn't have a dual 6pin to 8pin adapter but says he has a 6pin to 8pin cable that can run straight from the motherboard to the graphics card that will work cutting out the adapter. I apologize if this is a bit confusing and im new to uploading photos on here so another apology if its hard to see
134005000_1346224575728820_7698577405053026620_n.jpg
134408681_3467988179936829_2523275669746199317_n.jpg
 
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Ok, right. I agree, Dell has done a LOT of proprietary stuff, but, generally speaking, those systems were FULLY intended to ONLY be used in the manner in which they were set up and with ONLY the hardware they came with. Everything was spec'd for everything else. Adding significantly more demanding hardware to a system using a power brick type power cable, if that's what it is, is a terrible idea. We've seen these kinds of small form factor desktop systems that used laptop style power bricks, that were moderately more capable than those that come with most laptops but nowhere near what a desktop power supply can offer, create serious issues including ruined hardware, fires, fried wiring and everything sideways or in between.

Just because you can get an adapter for something doesn't mean it's wise to use it. It's really no different than the adapters we recommend against all the time that convert molex to six or eight pin PCI power. Or that adapt in other ways. If a power supply (Or whatever) was capable of supporting a given configuration, then 99 times out of 100 it would have come with that connector from the factory. The fact that it didn't tells us it was never intended to be used in that way.

That being said, knowing the full specifications of the power supply for this unit would tell us a lot, regardless of WHAT kind of power supply it is. Knowing a bit of something about the proprietary power convertors on the board itself would also probably be another good thing to know.

Personally, it's not something I'd ever recommend. Any system that can't support a standard PSU of some kind, whether it's TFX, SFF, mATX, ATX or whatever, and doesn't already have the required type and number of PCIe auxiliary connectors that are needed, is a unit that should probably not be used by that hardware in my opinion. I know not everybody is going to agree, but then again, there's a lot of people out there that can't even agree on the most basic, common sense driven things like wearing a mask during a pandemic so it really doesn't surprise me at all that there are always going to be detractors who insist that this or that is "perfectly safe" or that "it's fine". That's my two cents on that anyhow.
 
Yeah, checking the capability of the power supply is important for sure, especially for an external power supply like this. I'm actually surprised that there's 2x 6-pin leads like this, hence I would think it can run something with a single 8-pin, but who knows because the number of pins doesn't determine the ampage being pulled or the total wattage demand from a particular card.

Like always, power calculations are important to prevent overload, especially with cheap garbage power supplies that have infiltrated the US domestic market which causes fires and other hazards. (You can't sue these companies when it burns down your house since they sit happy with your cash in some foreign land; hence they produce this garbage and dump it on an unintelligent public.)
 
And, we also don't have the slightest clue if it came this way or if somebody has ALREADY adapted and modified something that shouldn't have been, so that it had the two six pins to start with. If I'm being honest I don't have any experience that I can recall on this specific configuration and model, but having worked on many others that were at least moderately similar I can't recall having ever seen a setup quite the same, and certainly no units with power brick type power supplies that had dual 6 pin or any kind of 8 pin feeds off the motherboard or any internal power board. Just seems wonky to me, but again, I guess I'm not 200% positive on that. If I don't know, I usually say so, and in this case I have to say I don't know that NO systems ever came that way, but I haven't seen one.