Discussion 4090 FE Connector melted with Cablemod Adapter installed. 40 series cards should be recalled

[zx128k]

Not a believer yet. We'll see.

Do what I do and just wait for the outcome to become clear.

 

[Diceman_2037]

I'm not surprised by this but the number of 6 or 8-pin connectors that have melted relative to the number of cards that have them is almost infinitely smaller than the number of nVidia cards with the new connectors that have melted. That's the very definition of a false equivalency.

False, stop spreading misinformation

 

[Avro Arrow]

False, stop spreading misinformation

Don't tell me, show me. I don't take people's word for things with useless posts like that, especially when I know that they're 100% wrong.

If my words were false, it would've been talked about when the 12VHPWR connectors were melting. People would've said "Sure, but it happens with standard PCI-Express supplementary power connectors too." but nobody did.

Furthermore, those connectors are the standard because before the advent of this oddball 12VHPWR connector that nVidia insists upon, EVERY SINGLE CARD that needed more than 75W used them. This 12VHPWR exists in only one generation of one brand of video card and there were enough of them to make the tech news and become general knowledge.

For standard connectors to have the same relative frequency of melting as the 12VHPWR connector, it would have had to have happened thousands of times over the past 20 years, but IT hasn't. I worked at Tiger Direct for years and would've heard about it for sure even if it didn't happen frequently enough to be general knowledge like the melting of the 12VHPWR is. Yet, I have never heard of it happening even once which means that it's not a thing.

These connectors overheated and melted because the conductors weren't in direct contact but were still close enough for the current to jump the gap between them, a process known as "arcing". It creates heat because air is an insulator and when electricity is forced to jump through it, the resistance skyrockets and friction-based heat is generated. If arcing were a risk with standard connectors, the card manufacturers would've included packets of dielectric grease with the cards for those connectors. They haven't done this because it has never been a problem, regardless of how much (for whatever reason) you may desperately need it to be so.

Don't worry, I don't expect an answer from you because there's no evidence backing up your nonsense.

 

[zx128k]

ATX 3.0 was was released in February 2022. It is an accumulation of new specs from draft ATX12V specifications dating back to 2020 as well as the 12VHPWR connector that PCI-SIG had introduced in November 2021. 12VHPWR was developed by the PCI-SIG for a spec sponsored by Nvidia and Dell.

The power connector is basically part of ATX 3.0.

BUT AREN’T 8-PIN PCIe CONNECTORS LIMITED TO 150W?

Not really. This was, like the current 8-pin adapter, a “catch all” spec that the PCI-SIG put into play back in January 2007 that took into consideration the many variables in the implementation of the PCIe cable, connector and terminals used.

A quality PSU like a Corsair, Seasonic, beQuiet, etc. will tend to use what is called Mini-Fit HCS (stands for “High Current System”). These terminals are specified to support 8.5 to 10A of current each (see dual row with 16 AWG and 18 AWG wire in the Molex Mini-Fit PLUS HCS spec). This makes the connectors actually more capable than the 12VHPWR connector. Even if Mini-Fit Jr. is used instead of HCS, the rating is A LOT higher than 150W per connector.

WAIT…. SO, ISN’T THIS A PROBLEM WITH THE NEW 12VHPWR CONNECTOR?

Well… yes and no. The specification for the connector and its terminals to support 450 to 600W is very precise. You are only within spec if you use glass fiber filled thermoplastic rated for 70°C temperatures and meets UL94V-0 flammability requirements. The terminals used can only be brass, never phosphor bronze, and the wire gauge must be 16g (except for the side band wires, of course). Unlike previous connectors on the market, there is no “pass” allowed to make cheaper connectors. If you make your cable any other way, you are not "within spec".

But there is an issue with the size of the terminals and their density. You are pulling more power through a smaller area, and this is going to generate more heat. But again, the connector is rated at 70°C based on the materials used. Even the best Mini-Fit Jr. connector directly from Molex is only good for 65°C.

So that brings us to the construction of the GPU. Historically, 12 to 14-layer PCBs are used with higher end graphics cards. Hopefully in time someone with the actual specifications for a 4090 PCB can reach out to me and I can update this article (confirmed that it's 14-layer, but copper density unknown). But I'm 99.9% positive that the graphics card's PCB is more than adequate for the card's power requirements with "normal" heat dissipation expectations. The reason why I'm even bringing this up witll come later....


SO, YOU’RE GOOD WITH THE 12VHPWR CONNECTOR?

Yes and no. I’m good with the connector on the GPU side as long as “rules” are followed. Proper material. Proper crimp. Proper wires. And I’m sure most GPUs out there have proper PCB layers, copper weight, etc.

Unfortunrely, a number of connector failures have cropped up since the launch of the 4090.

The connector itself is potentially good. I say "potentially" because it is very difficult to install. If the connector is not installed where it is completely flush and the latch securely locked in place, the connector could potentially "wiggle out", causing high resistence and result in burning. There are very few examples of this compared to the number of graphics cards in the field, but it goes without saying that when you spend $1500 on a graphics card and the power connector melts, it can be pretty upsetting. Telling people that "user error" is the reason for failure is a good way to piss people off. A connector like this should be more "idiot proof". Therefore, we can still fall back to this being a "design issue".

In conclusion, 12VHPWR is fine.. like I said months ago. But for now I will stick with only using them on the GPU side. And I make sure the connector is fully installed and latched by installing the cable to the graphics card BEFORE installing it in the PC.