Our post on Tuesday about melting 12V-2X6 connectors on RTX 5090 GPUs concluded with a grim prediction that we could see more melting power plugs on GeForce graphics cards. Well, you already know from the headline, but just to say it plainly — more power connectors are melting. Another GeForce RTX 5090 case has surfaced, but it seems like that fellow was foolishly mixing modular PSU cables, so the less said about that situation, the better. Much more concerning are a new RTX 4090 report as well as the first burned connector from an x80-class GPU.
First up, let’s quickly take a look at the new GeForce RTX 4090 issue. Redditor /u/schmidtyjon posted about his melted 12VHPWR connector to /r/NVIDIA yesterday. Fortunately for him, neither his GeForce RTX 4090 card nor his PSU suffered any damage, because the melted connectors were on the mating point between his PSU power cable and his MODDIY extension. He says “Unfortunately I was also one of the unlucky many caught in the CableMod 90° adapter debacle before this, and now after this episode, I’m so done with any adapters and extension cables from now on.” We don’t blame him.
Arguably more interesting—certainly more surprising—is the GeForce RTX 5080 that was seemingly affected. This one was posted by /u/Ambitious_Ladder1320 to the /r/ASUS subreddit; you can see one of his pictures up top. He was using an ASUS ROG Astral GeForce RTX 5080 card in combination with a ROG Loki power supply, the same PSU as /r/t0pli from Tuesday. Indeed, the user posted a “Call to Action” for other ROG Loki users, claiming that he has seen “similar reports from three other ROG Loki users on YouTube,” although he did not specify whom.
As we noted in the previous post, ASUS’ ROG Astral GPUs include a special warning indicator that shows when a 12VHPWR connector is not correctly seated. That light came on despite that /u/Ambitious_Ladder1320 claims everything was connected correctly. After troubleshooting, he realized that the 12VHPWR cable on the PSU side had suffered heat damage (pictured above). Fortunately, his GPU was undamaged. Notably, unlike some of the other cases, this user’s RTX 5080 was being powered by the 12VHPWR cable included with this ROG Loki power supply, not a third-party extension or adapter.
How could the RTX 5080, which draws considerably less power than even an RTX 4090, cause this kind of damage? Well, because the 12VHPWR and 12V-2X6 connectors have virtually no safety margin built in. This has been well-known for a long time, but it was reiterated today by Redditor /u/Affectionate-Memory4, who claims to be an electrical engineer working at Intel now, and formerly at ASML and Gigabyte.
Affectionate-Memory4 posted an extensive review of the 12VHPWR/12V-2X6 connector and cable on the /r/PCMR subreddit. His post goes into fine detail about the design of the connector and how it seems like it was really designed for a lower power limit.
Indeed, as he points out, the 12V-2X6 connector only allows a power draw of 375W at startup. This value makes a lot more sense as a power limit for the plug; it would give the connector a safety margin of 1.72x, which is much better than the 1.1x margin on the connector as it is rated at 660W—albeit still much worse than the more-than-2X safety margin on the older 6- and 8-pin connectors.
In this context, then, it bears mentioning that NVIDIA lists the Total Graphics Power (TGP) of the GeForce RTX 5080 as 360W. It’s well-known that GPUs can have significant momentary excursions beyond their base power draw, but more to the point, a single pin on the 12V-2X6 connector is only rated for 108W at a maximum, and if there’s a significant imbalance in resistance between the pins, there will be a significant imbalance in current flow over them.
It’s at this point that /u/Affectionate-Memory4 echoes Buildzoid’s commentary from Tuesday. In short, the GeForce RTX 40 and 50-series GPUs do not have the ability to balance the current load across the power connector’s pins whatsoever. He specifically says that this is likely a major reason for the burned connectors on the RTX 4090, and describes the RTX 5090 using the same design with an even higher power draw as “dangerous and potentially faulty”.
NVIDIA still hasn’t responded to this issue, but it’s only been a few days. We can imagine that someone at NVIDIA is probably in deep discussions over this, but it all comes down to whether more people with burned connectors continue to come forth or if it remains an isolated problem. Either way, it’s not a good look and we hope there’s some sort of resolution in the future.