Update: The Verge reports (opens in new tab) that Nvidia is investigating and will be contacting card owners regarding recent reports (currently two from Reddit) of power connectors melting on RTX 4090 graphics cards. [We also spoke with Aris Bitziopoulos of Hardware Buster to get his thoughts on the 12VHPWR power connector and its potential for overheating when bent Aris is a trusted PSU expert we employ for our Best PSU Guide for Gaming (opens in new tab) He is also our trusted PSU expert. In his tests, bending the 12VHPWR cable near the connector increased the measured temperature at the connection point by about 1°C.

The 12VHPWR connector used in the tests was a direct connection from an ATX 3.0 compatible Seasonic PSU, and Aris expects no problems with the connector in normal use. It is important to note, however, that this is not a test of the PCIe 3x 8-pin to 12+4-pin adapter included with Nvidia's RTX 4090, and it would be difficult to draw conclusions relevant to the later report on a badly damaged user power connector after failure. There are many variables; Aris mentions that care should be taken when bending cables to avoid damaging the pins.

The 12VHPWR connector, currently used on the original article Nvidia GeForce RTX 4090 (opens in new tab) graphics card and included in the ATX 3.0 specification, is not recommended to be bent during installation or use.

CableMod, a manufacturer of high-end cables, warns users that odd bends or folds in the cable can put extra pressure on the connector and increase the risk of overheating. The company warns users to beware of vertical bends and horizontal bends. In other words, users should aim to keep the cables perfectly aligned, otherwise they risk failure.

Anyone who has assembled a PC will understand that this is not always possible.

The 12VHPWR connector was introduced as part of Intel's ATX 3.0 specification (opens in new tab) and is intended to reduce the power footprint of the connector on the PCB and provide up to 600W of power. So far, it has only been adopted for use with the RTX 4090, but other graphics cards are expected to follow suit.

"While this new connector can provide the power needed for these power-hungry cards, there are some caveats that users need to be aware of," CableMod said in a post on its website (opens in new tab) dated September 25. [The 12VHPWR connector and the terminals used on it are much smaller than the previous generation. Through our extensive testing, it appears that bending a wire too close to the connector may cause some of the terminals to loosen or become misaligned within the connector itself.

"This can lead to uneven loading on the other wires, increasing the risk of damage due to overheating. This risk is considerably higher when the connector is bent horizontally with respect to its orientation (left to right)," CableMod notes.

Cablemod also states that bending of the 12VHPWR cable should be done 35 mm from the connector.

I bring up this post by the company today because a user on Reddit (open in new tab) posted that the 12VHPWR cable that connects the RTX 4090 to the power supply completely failed and melted in the process.

The unfortunate PC builder believes their setup was suitably simple and not too aggressively bent. The image provided by the user (opens in new tab) shows a slight bend, most likely more aggressive than Cablemod's recommended 35mm bend, but certainly not what one would consider a mistake or an anomaly by PC building standards.

You wouldn't think it was bad if you didn't know that one major cable company recommends such a bend.

"I don't know why that happened. I think my adapter cable is faulty. The card was installed vertically. The bending was not so severe. Sure there was a bend, but still, this shouldn't happen with a 2k euro GPU PSU Corsair RMX 1000," user reggie_gakil said in a forum thread.

At this time we cannot associate this single failure with bending or any other cause. We don't hear much about PCIe cables melting, new or old, but this is certainly not the first time it has happened. [but this new 12VHPWR connector is not without its critics either.

Overclocker and PCB analyst Buildzoid has already published a scathing review (opens in new tab) of the connector, calling it "the worst 12VHPWR connector" and noting that it has fewer pins for 600W of power delivery versus the old PCIe power connector and and has expressed concern about the need to change the power adapter in the first place.

WCCFTech (opens in new tab) has also been informed that PCI-SIG, the group responsible for the management of the PCI standard, is concerned about the implementation of some 12VHPWR and thermal variations when using adapters in PSUs with non-ATX 3.0 specifications, as they may lead to safety issues. We previously reported that we told its members to be cautious.

"We encourage our members to work closely with connector vendors and exercise due caution when using high-power connections, especially where safety concerns may exist," the PCI-SIG stated in a communication to its members.

However, NVIDIA has already attempted to allay the concerns of owners about this PCI-SIG statement. In response to the question, "Why did the PCI-SIG issue the warning and how will this affect Envidia's new products?", Envidia stated a month ago (opens in new tab):

"It will We will not. During initial development and testing, we identified a potential issue with a prototype connector produced by our only supplier. as a member of the PCI-SIG, we notified that supplier, asked them to correct it (they did), and shared our findings to assist the supplier in implementing the new standard. The PCI-SIG shared these learnings with other suppliers.

In other words, all connectors are fine, at least according to the GPU manufacturer's official position; the images posted on Reddit showing what can go wrong with a cable in the event of a failure are not pretty sights. Images posted on Reddit of what could go wrong with a cable if a failure occurs are not a pretty sight.

I would like to think that ratification of this connector by GPU manufacturers, Intel, Nvidia, and the entire PCI-SIG would be enough to assure that the cables that thousands of people will be using will not ignite just because they bend. The risk of fire should not be underestimated. (Open in new tab) That said, I would personally be inclined to follow Cablemod's advice if I were to use this cable within my own PC today.

Given this and the growing disquiet among some PC builders regarding cable safety, I can foresee some attempt by the aforementioned companies to quell further concerns. At the very least, to restore confidence in the safety of the connectors.