Melting cables are, once again, affecting high-end NVIDIA graphics cards, as a small selection of disgruntled GeForce RTX 5090 Founders Edition buyers and content creators take to social media to report unreasonably high temperatures radiating from its 600W connector. Noticing a “burning smell” while gaming, Reddit user “ivan6953” discovered their third-party MODDIY 12VHPWR cable had melted primarily around one of its pins, sparking a concerning sense of deja vu in the PC gaming community.
RTX 4090 GPUs were similarly stricken (albeit more widespread) with a dangerous problem affecting the last-gen 12VHPWR power connectors at its launch towards the end of 2022, which led to raised temperatures and eventually melting cables and posing serious fire risks that unfortunately continued happening to some unlucky users for months afterward.
Back then, the initial response blamed bent cables and insecure hookups, as even the slightest removal from a flush connection could cause issues, and third-party PC power supply brands moved to 12VHPWR cables with colored tips. It helped make it evident to even a novice custom PC builder when the cable was connected correctly, and NVIDIA’s internal redesigns supposedly made its new-style 12V-2×6 a safer option.
So, why are we seeing melted cables again?
YouTuber and PC enthusiast der8auer has been busy testing NVIDIA’s new RTX 5000 GPUs, as well as investigating the 12VHPWR cable issues associated with the RTX 5090. He originally discovered some abnormalities after connecting a Corsair 12VHPWR cable to his RTX 5090 Founders Edition GPU, and confirmed abnormal loads across cables with a thermal imaging camera.
He then uploaded the above video a few days ago, in which he analyzes Reddit user ivan6953’s actual hardware that melted and was sent to der8auer for testing. One of the cable sockets on the Reddit user’s GPU melted, a couple of PSU sockets melted, and the cable took most of the damage, with melted plastic and sleeving on both ends. Most concerning, one of the cables in the bundle took the brunt of the damage, suggesting that the power load was not being distributed evenly.
The Reddit user was employing a third-party MODDIY cable for their RTX 5090, which a lot of commenters called out quickly as being the problem. However, it’s not quite so simple. Der8auer discovered that the 12VHPWR cable simply does not have enough headroom to accommodate the RTX 5090’s power draw, resulting in the melted hardware. Der8auer states that “the RTX 4080 is perfect for one of these connectors [12VHPWR]. The 4090 and the 5090 should use two. Then you would have sufficient headroom.”
Der8auer ultimately came to the conclusion that the melted cable and hardware were not user error after speaking with ivan6953, who turns out to be an enthusiast with PC knowledge who took care to ensure the cable was plugged in fully each time he used it.
In a more recent follow-up video, der8auer backs up his claims in the original video with further test results. He notes that he’s not the only one discovering issues with the 12VHPWR cables, with the problems echoing the same we saw with the RTX 4090.
He summarizes the issue, stating that “RTX 40 and RTX 50 cards have no way to tell how much current is flowing across which of the pins.” That’s unlike older NVIDIA and modern AMD GPUs, which can tell how much power is being delivered with each connection. He specifically mentions the RTX 3090 Ti and its three-way split for the 12V power, which allows it to better balance the power load.
Der8auer’s conclusion — that the problem ultimately lies with NVIDIA’s power setup and the RTX 5090’s inability to sense how power is being distributed — makes sense. Unfortunately, there’s not really an answer as to how to solve the problem without making NVIDIA change its design.
I’d love to recommend one cable that won’t melt, but at this time it’s impossible. Your best bet is to use the highest-quality hardware possible, ensure it’s plugged in all the way at all times, and cross your fingers tightly.
