SKU CP-8920274 12-pin GPU Power Cable

[Hopper64]

The Asus Tuf 3090 Ti has the new 12 pin power connector, but the converter supplied with the video card appears to require 3 8-pin connectors:

 

https://www.guru3d.com/articles-pages/asus-geforce-rtx-3090-ti-tuf-gaming-review,3.html

 

There appear to be 3 8-pin connectors required towards the end of that page. I have a corsair AX1600i and I purchased the CP-8920274 cable, but only 2 8-pin connections are made to the PSU itself.

 

https://www.corsair.com/us/en/Categories/Products/Accessories-|-Parts/PC-Components/Power-Supplies/12-pin-GPU-Power-Cable/p/CP-8920274

 

So is the CP-8920274 adequate to supply power (>400W) to this graphics card? What confuses me is that people quote 150W per 8-pin connection, so I’m thinking there’s no way to get to >400W with only 2 8-pin connections to the PSU even with the 75W on the PCIe slot.

 

Thanks!!

[jonnyguru]

On 8/17/2022 at 10:21 PM, Hopper64 said:

There appear to be 3 8-pin connectors required towards the end of that page. I have a corsair AX1600i and I purchased the CP-8920274 cable, but only 2 8-pin connections are made to the PSU itself.

Required?

No.

They provide an adapter with three 8-pins because you're adapting from existing, full length cables of unknown wire gauge and quality.  There's a difference between that and using a complete cable from PSU to GPU and that.  

If you have a Corsair PSU and you use a Corsair 12-pin cable, then you're fine using just two 8-pin Type 4 connectors on the PSU side.

[Hopper64]

Then how would the corsair cable CP-8920274 be able to provide over 400W to the card if there’s only 150W per 8 pin connection? That card pulls well over 400W during load.

[Hopper64]

As a follow up, what about cablemod custom cables? They have one for the 3090 ti with 3 8-pin connections and their reputation for quality is quite good from what I am reading. Would this be an appropriate alternative? Thanks.

[Hopper64]

Found this with a quick search:

https://www.gpuminingresources.com/p/psu-cables.html

So my concern for max power per 8-pin connection is unfounded if this is accurate. With the quality Corsair AX1600i that I am using, each 8-pin can supply 288W for a max of 576W + the PCIe slot at 75W. I’m underestimating the capacity of the cable. It appears to be able to supply much more juice than I had originally anticipated. I just wanted confirmation of this before proceeding with any change in how I’m powering the card.

[jonnyguru]

On 8/23/2022 at 4:03 AM, Hopper64 said:

Then how would the corsair cable CP-8920274 be able to provide over 400W to the card if there’s only 150W per 8 pin connection? That card pulls well over 400W during load.

No.. 150W is not a cable spec. It's a spec for the card.  PCIe cables are capable of much higher wattages.  Typically at least 2x the power.

The “weak link” in a cable is the terminal and not the wire gauge. The most commonly used 18g Mini-Fit terminals support 9A each. Some better PSUs use 16g HCS (High Current System) which supports 13A each terminal.

This results in a 432W limitation for typical 8-pin Mini-Fit connector 18g terminals if all eight terminals on the PSU are populated, and 624W for 8-pin connectors with 16g HCS terminals if all eight terminals are populated. If only three terminals of either row are populated, then your limitation is 324W and 468W respectively. Therefore, PSUs that use standard mini-fit terminals with 18g wire for their PCIe pigtail cables are not recommended for 450W+ cards.
 

[Hopper64]

So how do you know the specs of the cables on your PSU? I have a Corsair ax1600i. I just received a cablemod 3 8-pin to 12-pin made specifically for Corsair PSUs. Running MSI Kombustor everything worked fine. Gaming works fine. Same with the adapter with the video card and Corsair's  2 8-pin connector to 12-pin as above. Thanks for your help.

 

I attached a baseline picture with the adapter, the Corsair cable directly from the PSU, and the Cablemod cable directly from the PSU:

 

[Hopper64]

So here is another source on this subject:

 

https://wccftech.com/atx-3-0-12vhpwr-gen-5-connector-major-safety-risk-using-adapter-confirms-pci-sig/

 

So what do you make of this? And I saw your comments here:

 

https://www.techpowerup.com/296760/corsair-announces-the-2022-hxi-power-supply-series

 

So just plug in the 8 pin connectors and not worry about it? It’s really confusing.

[Hopper64]

No other input from corsair? I the first reference above, it may be a load balancing issue: 25A on one connector while the other 2 are 7.9 and 6.4 Amps. It’s recommended to have an updated PSU with the upcoming 4090s. ATX 3.0 PSU. Does corsair have any?

[LeDoyen]

that's pretty certain they have some in the works.

From past experience, they almost never announce products in advance. 

[Hopper64]

But there was the new 1500W PSU announced as above:

 

https://www.techpowerup.com/296760/corsair-announces-the-2022-hxi-power-supply-series

 

But there’s no 16 pin on the PSU side. The comments are revealing to me. I was hoping for some clarity here but it’s still quite confusing. And then in the other link I posted, there’s the concern about a safety risk with using an adapter. I wish we had something definitive about using an ATX 2.0 PSU with and adapter or a custom cable from the 8-pin connection on the PSU to the 12/16 pin to the GPU.

[LeDoyen]

they are announced right when they are launched, not before launch. that's what i was refering to. That's usually how it goes with Corsair.

Remember Corsair (to my knowledge) now develops all their new PSUs in house, and do not contract another OEM. So it will probably come out a bit later. it's bloody long to test and fully validate a new design that you will then confidently cover with a 10 years warranty. You can have a few crumbs of informations on the video that Gamers Nexus did at Corsair with JohnyGuru regarding PSUs, like the new type 5 cable standard.. and a few slips here and there 🙂

The power supply are coming, there's no doubt about that, but there's no need to rush to a market that is nonexisting as of today.

[Hopper64]

Yea. I’m just looking to get a 4090 at some point and want to be prepared. And there’s so much misinformation that it’s difficult to sort fact from pure speculation at times. Thanks for your reply!! 🙂

[LeDoyen]

i may be wrong, but looking at the intel guidelines for ATX3.0 it seems some details of it are still being finalized, or have been very recently.

So yea i wouldn't jump on the first PSU to claim compliance just yet. I only gave a quick glance at the spec and so much is changing it's going to be a marketing fest, praying on customers not being familiarized with it at all.

Best to wait for those GPUs to actually come out and to have independent test results on those power supplies to make sure they actually meet the standards. Early adoption is a mined field.

[Hopper64]

No doubt about that. Thanks.

[Hopper64]

Here is a little information from Nvidia via techpowerup on the issue of PSU necessity with the upcoming GPUs:

 

NVIDIA made it clear the existing power supplies will work fine through the use of adapter cables, a ATX 3.0 PCI-Express 5.0 power supply is not required for Ada Lovelace GPUs.

Source:

https://www.techpowerup.com/299096/nvidia-details-geforce-rtx-4090-founders-edition-cooler-pcb-design-new-power-spike-management

[Hopper64]

Of course that’s the FE card whereas the other vendors may have different requirements.

[Hopper64]

So here’s a custom Zotac  card with a 4 8-pin adapter, not just a 3 8-pin adapter with a major caveat:

 

https://www.techpowerup.com/299162/8-pin-pcie-to-atx-12vhpwr-adapter-included-with-rtx-40-series-graphics-cards-has-a-limited-service-life-of-30-connect-disconnect-cycles

 

Limited service life with the adapter.

Edited September 23, 2022 by Hopper64

[LeDoyen]

Depends how often you like to take your GPU out for display purposes on a shelf? 😛

i may have disconnected my PCIE cables a grand total of 3 times since i got my GPU. But ideally you want to get rid of those adapters and use the 12VHPWR cable made by your PSU OEM anyway. Less contacts, less losses, less heat.. and the cable clutter of that 4 PCIE squid must be spectacular.

[Hopper64]

Yes, but why have such a limitation as ridiculous as it sounds? Might be some issue arising due to the adapter not being up to the task. Makes you wonder.

[LeDoyen]

well, connectors are tight the first time you use them.. less so after several cycles.

When dealing with low voltage and high current DC,  you want tight contacts.. otherwise the contact resistance increases. and if they start to warm up a little, it cascades.. more oxydation, more resistance, more heat, more oxydation etc etc..

even today you can burn up your PCIE connectors if they are crap quality or too old and somewhat loose. That's why i usually discourage people from using sleeved extensions, making a pretty build that is now ready to smoke.

This generation, they just pushed current draw higher, The cables and connectors are still in spec i'm sure, but now they have to bring under attention some other specs that were not important before.

 

[Hopper64]

What’s your thought on the custom cables provided by cablemod then? They have both 2 and 3 4-pin connectors to the single 12-pin available through their configuration utility. It’s based on your own PSU brand and you can order specific lengths and color combinations. Their reputation is good but some are still reluctant to go that route. They advertise high gauge wire as well although it’s not specific on their website. It’s the only solution to keeping a cable color theme if desired as I don’t see that option available yet at Corsair.

[LeDoyen]

that tiny 12 pin may be a bitch to sleeve with thick gauge wiring ? hehe

Maybe Corsair is working on sleeved ones. it's still very early.

I wouldn't have any issue using the corsair unsleeved cable though. Swapping 2 or 3 big sleeved cables for a tiny one won't be an eyesore. But i personally always put reliability before aesthetics. That said Cablemod is a reliable supplier, and i wouldn't have any issues trying out their cable. just my 0.02$

[Hopper64]

I agree. I have tried them after being quite reluctant, and they seem to have a quality product.

[Hopper64]