Help with connecting 2x GTX580 - Cable confusion

7rigg3r

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Jul 9, 2008
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Hi!

English isn't my native language so bare with me... :)
I'm building my new rig, 5 years since last build. Got a lot of help choosing parts from you guys here at the forums. After I installed everything and booted up, fans started but no image on screen and I realized, after some reading, that my GPUs wasn't correctly plugged in. The GTX580 needs a lot of juice but I find the manual lacking in explaining how to plug them in...or maybe I'm just daft. After reading some reviews and forum posts I got a little nervous since one guy followed what he thought was the correct way to plug in the card and got a card giving of smoke...not good.

I've read posts where people say you don't need to use the adapter cable 2->1 and other posts saying your card won't perform optimal without it or even work properly. I sure don't want to fry my cards so I'm really looking for some help and pointers here!

Here are some pictures of what I have and what it looks like. I would really appreciate some instructions on how to connect my cards and what cables to use!

Info in GPU-manual:


Included adapter-cable: (one for each GPU)


PSU_Connections:


Included cables that comes with the PSU: (got two of these)


GPUs with cables I connected at first:



Full spec of components:

PCPartPicker part list (Link includes most of the parts)

CPU: Intel Core i7-3930K 3.2GHz 6-Core Processor
CPU Cooler: Noctua NH-D14 SE2011 CPU Cooler
Motherboard: Gigabyte GA-X79-UD5 EATX LGA2011 Motherboard
Memory: G.Skill Ares Series 16GB (2 x 8GB) DDR3-1600 Memory
Memory: G.Skill Ares Series 16GB (2 x 8GB) DDR3-1600 Memory
Storage: Samsung 840 Pro Series 512GB 2.5" Solid State Disk
Video Card: Gainward GeForce GTX 580 - 1536MB "Phantom"
Video Card: Gainward GeForce GTX 580 - 1536MB "Phantom"
Case: Fractal Design Define XL R2 (Black Pearl) ATX Full Tower Case
Power Supply: Cooler Master Silent Pro Gold 1200W 80 PLUS Gold Certified ATX12V / EPS12V Power Supply


Thanks in advance! :)

 
Solution

austing

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You should have two of those PCIe cables that came with your power supply. Each cable has ONE gold end that goes into the power supply, and at the end of that should be ONE 6 PIN, and ONE 6+2 pin.

What you're going to have to do is get 2 of your PCIE cables, plug one of them in, and take both cables that come from that cable to plug into the GTX580.

Take the second cable, plug it in, and then plug BOTH of those cables that come from the end of that into the SECOND GTX580
 

7rigg3r

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I plugged in the cables already coming out of the PSU into the GPUs, one for each GPU, but I didn't get an image/bootscreen. What's the diference between connecting it this way and connecting the seperate cables to the PSU and then into the GPU's? It's the same connectors, do these cables supply more/different power or am I not understanding you correctly? What about the 2->1 adapter that the manual says is necessary to power the GPU?

Sorry if I'm asking stupid questions or if this has been answered before, but I really want to understand this and be sure I won't fry my cards before I boot up. I did boot up with them connected with one cable to each card but the screen diddnt display anything. One cable to each card like in this pic:

Holding one cable and one loose in pic. Each cable was connected to one card each.

 

austing

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You have to make sure all 4 cables are plugged into each graphics card.

Make sure you have each 6+2 pin cable connected, and each 6 pin also connected.


PCIE on power supply (gold 6 pin, into the gold hole) > PCIE cable #1 > Graphics card #1 (6+2pin and 6 pin)
PCIE on power supply (gold 6 pin, into the gold hole) > PCIE cable #2 > Graphics card #2 (6+2pin and 6 pin)

What you're talking about is an adapter that comes included if your power supply doesn't have a 6+2 pin, which your powersupply has.

I wouldn't use cables for my powersupply that don't come with it.
 

7rigg3r

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I'm sorry if I don't understand you! I don't see a difference with what I did try and what you suggest. I might misinterpret what your telling me but this is how I understand what your suggesting. Does it suply more power coming from the goldcables than from the regular ones?

I had it like this:


Your suggesting this?:

 

7rigg3r

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Thanks for your help austing!

New rig now up and running :)
I've seen pictures online where they have two cables connecting to each GPU, instead of one as it's set up now. How does this differ from my current setup? Since it provides more power to the cards, does it boost performance and if so, in what way and what would I benefit from hooking it up like that? How exactly should I connect it? What about the adaptercables provided? It baffles me that this information is so badly shown in the manual and online...at least what I could find.

I don't want to jeopardize my cards but at the same time I want to make sure I'm using them to their full extent. My goal with this setup is to maximize performance in 3D-rendering and reaping full benefit from the CUDA cores. Any thoughts, hints and pointers?
Glad for any help here since I haven't found any good information on how to best set up/connect the cards in the best way online.

Thanks in advance! :)
 

austing

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Your powersupply has a stronger voltage rail that goes into that power connector, which is why only one cable has two connectors. There is no difference in power delivered between a case that requires 2 cables, and yours.

You cannot deliver more power to the card unless you overclock in while on the computer (You can make the card draw more power so that you can clock the GPU higher and be stable)

Look up your specific card, and an overclocking review, you can pretty much just copy their preset for the GPU's overclock
 
Solution