3080 FTW3 PCI-E Cable Question

[3t3P]

So when/IF I get my 3080 FTW3 I want to feed it as much clean power as possible.

Currently I have two Pig tailed wires giving me x4 6+2 Pins from two connections into the PSU.

In all likelihood I'm thinking this will be fine as Corsair will have rated each pigtail to 300W. It's also listed as a single rail circuit design, so electrically having three separate wires will make no difference.

Here's a pic of the PSU end, note 7 Pins active:

Now I dug around my wire collection, to see if I can feed EACH 8 pin connector on the 3080 with its own wire. Here's what I found, this is the PSU end of a 6+2 PCI-E cable:

Six pins, I believe the 'lost' pin in the top right is a ground wire.

So is this a 150W PCI-E cable that I can use on a GPU?

 

[Rom]

Is that for the same PSU? Or just a cable you had laying around? There is no standard pinout for psu end, so dont just go plugging it in unless you are sure, or test it.

If its any help, my 3080 FTW Ultra has 2x8 pin pcie (direct cable from psu, 1 connector on each cable) and 2x6 pin pcie into an EVGA adapter (2x6 into 1x8).
Im on the new bios, pulling 450w, roughly equal across the connectors.
I do have a new psu which will be 3x8 pin pcie when I get a Ryzen 9.

 

[3t3P]

The cable was I'm very sure amongst others for this PSU.

Corsair usually print on them if they are model specific this cable has no such marking.

Wondering if I should just use one daisy chained PCI-E cable to populate two 8 pin connections on the card and use one remaining pig tailed connection (but only use one plug) to make up the third 8 pin power requirement on the card.

Amazing you even got a card! How's it doing on 450w BIOS?

 

[Rom]

It arrived on the 8th. Very lucky!

It's doing great, but still perfcap PWR in gpuz during benchmarks!

So if you use the pig tails, it can't actually draw anymore can't it? It's 150w per 8 pin off the psu I think. So 2 8 pins off same cable is still only 150w?

 

[pastymuncher]

I would not be using the daisy chained connectors. I have seen plenty of end connectors melted by a component drawing too much power down the leads. There was even one on here quite recently. I would only be using the primary cable from each lead.

 

[3t3P]

Pigtails would be designed for 300W

 

[pastymuncher]

That may be so but we have seen many problems using pigtails to power high power cards including crashes, black screens and as I already mentioned, molten plugs due to the card pulling too much power down a single lead (CPU's can also do this to the 12v EPS lead and was a problem with high end AMD FX series CPU's). The AMD Vega cards and some 2080ti's suffered from crashes and black screens when powered by daisy chained connectors. Once powered by two seperate pci-e leads the problems were cured.

 

[3t3P]

I contacted Corsair who are getting back to me.

Worst comes to worst can buy a legacy cable from corsair for a tenner delivered

 

[pastymuncher]

Corsair are only going to tell you what you want to hear. They are going to leave you with no doubt that the cables are more than good enough to do the job. If/when you have problems don't forget that we told you how it really is.

 

[3t3P]

Well I've linked them this thread so we shall see

 

[chaparral]

Corsair are only going to tell you what you want to hear. They are going to leave you with no doubt that the cables are more than good enough to do the job. If/when you have problems don't forget that we told you how it really is.

I agree

There no way Corsair going to come back and say you can't use the daisy chained connectors on there own cables

 

[mickyflinn]

I agree

There no way Corsair going to come back and say you can't use the daisy chained connectors on there own cables

I agree but he question really is does the 8 pin daisy chain cable carry 300w or 150w, there is some confusion around this for many people.

They think that because the 8 pin is rated a 150w the single cable daisy changed 8 pin connectors still only carries 150w.

 

[3t3P]

Some here are getting distracted by what my actual question is. That is, about the cable I found and compatibility with my PSU.

The daisy chain cable has two 8 pin connections on it, that makes it a 300watt cable.

300 watts is nothing special at this guage. It's a small to medium sized R/C plane amount of power, nothing mental. If it's made well it won't be a problem.

 

[Rom]

I agree but he question really is does the 8 pin daisy chain cable carry 300w or 150w, there is some confusion around this for many people.

They think that because the 8 pin is rated a 150w the single cable daisy changed 8 pin connectors still only carries 150w.

I know we are wandering off topic...

From my understanding, 8 pin spec is 150w. Though they are 'capable' of more. Im assuming its down to the cards pcb etc to limit it to that spec of 150w per 8 pin.
If you use 2 8 pins, from 1 cable from the psu. The cable must be rated to carry 300w? Because it only has the same amount of 12v pins as a single 8 pin supplying it. Yet drawing twice the power as its 2 connectors. If not, psus would be breaking and melting etc. They wouldnt supply a cable that would melt if you used it how its designed (ie use both 8 pins on a single cable)

The spec for 8 pin, and 6+2 is the same from what I understand. Both should have 3 12v wires, rest are grounds (6 pin can be 2 or 3 12v wires).

If you have a multimeter, to be sure, I would probe them. Then you have your answer. My guess is its missing a ground, not a 12v

 

[Quartz]

What gauge is the wire? That will tell you the current it can carry.

 

[3t3P]

The spec is 150w per connector but capable in reality of carrying more.

I've had a second reply to Corsair, missing the mark and in grammatically broken English. They've basically said my PSU has enough power. I'm going to message back.

 

[pastymuncher]

This is what can happen when a gpu pulls too much power down a single lead. That was a quality Seasonic 1000w psu as well.

 

[3t3P]

This is what can happen when a gpu pulls too much power down a single lead. That was a quality Seasonic 1000w psu as well.

thanks but again, per my opening post this is not what i'm asking

 

[3t3P]

Corsair have confirmed that the cable is a full 150W 6+2 connector for my PSU.

 

[mickyflinn]

Corsair have confirmed that the cable is a full 150W 6+2 connector for my PSU.

Glad you got it sorted.