[SOLVED] 3070ti Cables...

[algypan]

Hiya.

I currently have a rog strix 3070ti and it has 3 PCI-e ports on the top of the card (three 8Pin). However I have noticed my PSU only has 2 slots for PCI-e cables on the actual PSU, as in two 8 pin. It is an NZXT 750 C series that I bought around 6 months ago.

For the moment, my card is hooked up with a cable that's daisy chained and it looks quite ugly to be honest. Do I need to aquire another PSU so I can run 3 seperate PCI-e cables from the PSU to the card? Is there any kind of performance or power hit or advantage to doing this?

Many thanks for your help!

Allan.

As a side not while typing this, could this have something to do with the constant VGA LED that's constantly illuminated on my z390 motherboard? ...seems coincidental that I've only noticed this light after installing the 3070.

Anyway, thanks again!

 

[--SID--]

my PSU only has 2 slots for PCI-e cables on the actual PSU

One CPU slot can be used for PCI-e. The pinout is the same.

 

[DRagor]

One CPU slot can be used for PCI-e. The pinout is the same.

I see two problems with this. First, this PSU comes with only 2 PCIe cables. Second, this model does not seem to support this kind of 'swapping' cables as others do.

 

[--SID--]

First, this PSU comes with only 2 PCIe cables.

It's a Seasonic OEM. Just buy a Seasonic PCI-e cable.

Second, this model does not seem to support this kind of 'swapping' cables as others do.

Why do you think so?

 

[DRagor]

Why do you think so?

Because it does not mention such option in manual. And if it doesn't, the only safe option is to assume that it won't work. Unless you have that model and made it work.

 

[--SID--]

Because it does not mention such option in manual. And if it doesn't, the only safe option is to assume that it won't work. Unless you have that model and made it work.

Seasonic use the same pinout for CPU and PCI-e on the PSU side and all pins in the CPU and PCI-e connectors are shaped the same. If the pinout would be different also the pins should be shaped different to prevent user errors.

 

[DRagor]

If the pinout would be different also the pins should be shaped different to prevent user errors

"Should" being the key word here. Unfortunately not all manufacturers think same way. Unless you can find a reliable source that states that pinouts are same on this model I'll consider this to be a big no no. A price to pay in case of error is too big for the OP.

 

[Zerk2012]

Seasonic use the same pinout for CPU and PCI-e on the PSU side and all pins in the CPU and PCI-e connectors are shaped the same. If the pinout would be different also the pins should be shaped different to prevent user errors.

Look different to me.
https://cdn.mos.cms.futurecdn.net/cHcM2cQgYkTEGUETEzt6kZ-1707-80.jpg

https://www.tomshardware.com/reviews/nzxt-c750-power-supply-review

The same pinout is on the Seasonic.
https://cdn.mos.cms.futurecdn.net/UZgM42XJjt68zFN3gFgdWB-1707-80.jpg

 

[DRagor]

That's actually interesting. This is how this model looks on nzxt page:

and this is how it was looking in Tom's review:

Bottom right slot is named differently. Now, the review states that PSU came with one EPS cable (so no need for two connectors), but nzxt said they will supply them with 2 EPS cables. Whether that means that pinouts were indeed same and they just changed the label, or whether they actually changed something inside is unknown though. So SID might be right, but again without hard evidence am skeptical.

 

[John Chesterfield]

SID's probably on the money, he's well up on power supply OEMs and can often point you in the direction of a power supply brand that normally hasn't such a good reputation, but has the odd good OEM and a 7 or 10 year warranty. Your above post makes sense and would seem to confirm his suggestion, as those markings on there are not always done by the OEM. Every chance he's right.

And if he's not and it doesn't work and something were to go wrong, if the pinout is the same on the outside, there'd be no damage to the plug socket on the power supply and you could just claim the warranty.

Odds on he's right though. But I'm not understanding the OP's cable situation, is he or she saying that they have 2 x cables with just a single connection on the end? Because they normally give you a daisy chained one as well.

If the Seasonic cable were to fit in the socket on the outside of the power supply without issue, which you can try with everything powered off and nothing connected to the other end of the cable, I'd wager that SID's correct in what he says.

 

[Zerk2012]

That's actually interesting. This is how this model looks on nzxt page:

and this is how it was looking in Tom's review:

Bottom right slot is named differently. Now, the review states that PSU came with one EPS cable (so no need for two connectors), but nzxt said they will supply them with 2 EPS cables. Whether that means that pinouts were indeed same and they just changed the label, or whether they actually changed something inside is unknown though. So SID might be right, but again without hard evidence am skeptical.

Then to throw some more crap into it he might not even have the Gold one same 750 C but bronze
https://nzxt.com/assets/cms/34299/1...orts.png?dpr=1.5&fit=crop&fm=webp&h=576&w=576

Amazon image.
https://m.media-amazon.com/images/I/71bEvmr9IZL._AC_SL1500_.jpg

And yet another review site image.
https://latestintech.com/wp-content/uploads/2021/01/NZXT-C750-Review-11.jpg

PCPartspicker image LOL.
https://cdna.pcpartpicker.com/stati...uct/cbb68f1d54a099f841102cc5e0a73376.1600.jpg

Newegg image.

https://c1.neweggimages.com/ProductImageCompressAll1280/17-116-040-S01.jpg

The design could of been changed so who knows.

 

[Zerk2012]

SID's probably on the money, he's well up on power supply OEMs and can often point you in the direction of a power supply brand that normally hasn't such a good reputation, but has the odd good OEM and a 7 or 10 year warranty. Your above post makes sense and would seem to confirm his suggestion, as those markings on there are not always done by the OEM. Every chance he's right.

And if he's not and it doesn't work and something were to go wrong, if the pinout is the same on the outside, there'd be no damage to the plug socket on the power supply and you could just claim the warranty.

Odds on he's right though. But I'm not understanding the OP's cable situation, is he or she saying that they have 2 x cables with just a single connection on the end? Because they normally give you a daisy chained one as well.

If the Seasonic cable were to fit in the socket on the outside of the power supply without issue, which you can try with everything powered off and nothing connected to the other end of the cable, I'd wager that SID's correct in what he says.

Without even knowing if he has the gold or bronze model it's impossible to tell and even if he has the gold their showing 2 different versions from all the links so who knows.

 

[DRagor]

And if he's not and it doesn't work and something were to go wrong, if the pinout is the same on the outside, there'd be no damage to the plug socket on the power supply and you could just claim the warranty.

I would be more concerned about GPU. If the pinout is wrong, I'd say it's 90% chance to fry the GPU, and actually healthy chance PSU will survive the experiment. We talking 3070ti here so at least 1000$ bet. I would not risk for sure.

I'd wager that SID's correct in what he says.

Actually that's the least important thing. What REALLY matters is that OP now knows all the possible dangers of using SID's solution. With that, Earth out, peace and Happy New Year.

 

[Zerk2012]

To be on the safe side the only way I would do that would be doing this first. At the about the 2:30 mark he says never assume.

View: https://www.youtube.com/watch?v=opFTzO1s1WA

 

[algypan]

I can only thank you for all the help all of you have offered. I have the gold one if that makes a difference. Also with refererence to the daisy chain situation I have.... Please bare with as I try to explain this... On the PSU I have two 8 pin cables coming from the 2 PCI-e sockets on the back, one of those seems to have a spure (the daisy chain piece) that has a 6+2 connector which obviously goes straight into the other 8 pin socket on the card which now has all three connections occupied.

I have discovered that with my PSU, the 750 only has two 8 pin PCI-e sockets on the back, where as the 850 appears to have 3 and the 850 also comes with three seperate PCI-e 8 pin cables.

I am very sorry to be a pain in the ass. I'm probably not explaining this all too well either.

 

[John Chesterfield]

Preferable for me to have separate cables, but a lot of people here will tell you it's fine to run it that way. Do you have it running then?

 

[John Chesterfield]

I would be more concerned about GPU. If the pinout is wrong, I'd say it's 90% chance to fry the GPU, and actually healthy chance PSU will survive the experiment. We talking 3070ti here so at least 1000$ bet. I would not risk for sure.

You're not getting what I am saying. Look at the sockets, the CPU and PCI-E ones are exactly the same combination and sequence of shapes. So you could plug these in without damaging the socket. If those were different electrically, the manufacturer would have chosen a different set of shapes for each connection. Making these two the same while they were different electrically is helping the end user to fry their unit. I really don't think they'd do that, maybe years ago but not now.

 

[DRagor]

I have discovered that with my PSU, the 750 only has two 8 pin PCI-e sockets on the back, where as the 850 appears to have 3 and the 850 also comes with three seperate PCI-e 8 pin cables.

Yes, that's correct. Here comes a catch: some of the 850 cables will still be daisy chained. So if you use 3 of them, there will be some loose connectors dangling from your GPU which will not look good either. If you are so much about the looks then you might need custom cables (plus PSU that allows 3 PCIe cables, we didn't come to agreement if yours does).