AMD to Ditch 12-Pin GPU Power Cable as Photos Appear of Melted RTX 4090 Adapters
GPU “Cable Gate” is an official thing now. This week a Redditor posted images of a melted 12-pin adapter cable on their Nvidia RTX 4090. The power plug on the PCB was also irreversibly damaged as well. Naturally, the Internet was outraged as this was predicted to happen before the GPUs launched. Back in September PCI-SIG issued a warning about using 12-pin power cable adapters, saying it could cause problems. Now, that has apparently happened. In the wake of this event, it’s been confirmed that AMD will not be using the new cable on its upcoming RDNA3 GPUs. This has led to a lot of questions about Nvidia’s 12-pin cable design. Now Nvidia says it’s investigating the incident.
Backing up a tiny bit, the 12-pin power connector is not a new thing. Back when Nvidia launched its Ampere architecture, it also introduced a new 12-pin power connector. This change allowed for more room on the PCB, as it went from dual 8-pin connectors on high-end cards to a single 12-pin, mounted vertically. Nvidia used that extra space to improve cooling performance. The GPUs included 8-to-12-pin adapters, and all was well. However, things have changed with the introduction of the RTX 4090.
A new ATX 3.0 and PCIe 5.0 spec provides a single 12-pin cable (above) from the power supply to the GPU. This connector, dubbed 12VHPWR, differs from the Ampere cable; it has four additional signaling pins that communicate with the GPU. However, PSUs with the new cable aren’t readily available yet, so you have to use an adapter. For the RTX 4090, it’s typically a four-into-one adapter using 8-pin cables.
Previous reports suggested these adapters could cause issues with new, high-power GPUs when using ATX 2.0 power supplies and adapters. PCI-SIG sent a letter to its members warning them about this scenario. According to Wccftech, it stated, “Please be advised that PCI-SIG has become aware that some implementations of the 12VHPWR connectors and assemblies have demonstrated thermal variance, which could result in safety issues under certain conditions.” Thermal variance seems to be the key phrase here.
Now a Redditor has posted photos of a melted cable and connector on an RTX 4090. In the same thread, someone posted a second image of a melted connector as well. Additionally, when YouTuber Jayztwocents made a video about this controversy a while back, Nvidia told him there was nothing to worry about. It said it’s done its testing and there were no issues.
As far as Reddit goes, a rep for Nvidia has apparently reached out to the Reddit user. Now its PR chief says the company is investigating. In a statement to The Verge, Bryan Del Rizzo said, “We are investigating the reports,” adding they are collecting information from Reddit users.
Following this imbroglio, it’s being reported AMD will not be using that cable at all for its upcoming RDNA3 GPUs. Instead, it’ll use a traditional dual 8-pin configuration, at least on the high end. That’s what sources have told Kyle Bennet, formerly of [H]ardOCP notoriety. This was then confirmed by an AMD SVP. This applies to AMD reference cards only. It’s unclear if partner boards from MSI and others will also jettison the controversial connector. It’s also unknown if a cable capable of pulling 600W will even be necessary for AMD’s next-gen.
After all, if AMD’s high-end card only requires two 8-pin connectors, that’s a 300W budget. Add in 75W from the PCIe slot and you’re looking at a sub-400W GPU, compared with Nvidia’s 450W card. It’s possible that AMD’s solution is much more efficient than Nvidia’s as well. That’s simply because it will be the first consumer GPU with a chiplet architecture. This stands in contrast to Nvidia’s enormous monolithic die for Ada Lovelace.
Still, it’s a stumble for Nvidia’s newest GPUs. It remains to be seen what is the exact culprit for the melting behavior. When the GPUs launched some reviewers called out the scary amount of bending required to tuck the cables away. When you bend the adapter down to hide the cables, it puts a lot of pressure on the connector attached to the PCB. This could pry its connections loose from the PCB over time, some predict. The issue is exacerbated by how large the GPUs are too, as it can place the connector close to the side panel. As an alternative, CableMod sells a 90-degree adapter to prevent flex at the connector. The other alternative is to buy an ATX 3.0 PSU, but they are still not as prevalent as ATX 2.0 models, which are ubiquitous.
For now, we will have to wait and see what Nvidia has to say when its investigation is completed. People spending $1,600 on a GPU don’t necessarily want to drop another $200+ on a new ATX 3.0 power supply, so the adapters are necessary. But if those adapters are causing issues, they might not have a choice.
Nvidia and its partners have surely shipped thousands of GPUs to customers, if not more, and so far there are only two published reports of melting occurring. Still, it’s concerning it has even happened once.