User reports melted power cable on an RTX 5070 and now we’re wondering

An X user has posted videos of an RTX 5070 that has suffered an all-too-familiar case of cable meltage. Reportedly, an updated 12V-2×6 power cable is implicated, as opposed to the older but closely related 12VHPWR cable, which is a worry.

For the record, the card in question was a Zotac RTX 5070 model paired with a Seasonic Focus GX-750 power supply. It’s worth noting that it was the cable that suffered unambiguous damage here, not the graphics card or even, seemingly, the power connector or socket.

That’s eerily familiar from investigations made earlier this year by YouTube creator Der8auer, where it was found that the power across the multiple cables in both 12V-2×6 and 12VHPWR connectors attached to the Nvidia RTX-50 series was highly imbalanced.

Der8auer tested the six live cables on these connectors hooked up to an RTX 5090 and found that the power isn’t evenly balanced across all six wires. In fact, just one wire was loaded with 250 W and thus roughly half the load generated by the 5090.

Consequently, that heavily loaded wire was getting dangerously hot. An RTX 5070 is clearly a much lower-power GPU, rated at 250 W TDP versus the 5090’s 575 W. But if a 5070 is pulling all of that 250 W or something close to that over a single wire, well, you get the idea.

As for why this happens at all, in other words why the power isn’t more evenly distributed over the cables, I explained back in February, “some AIB RTX 5090 designs include per-pin power sensing, which would presumably stop this kind of power imbalance from happening. But, surprisingly, Nvidia’s own FE design apparently does not. Instead, it essentially amalgamates all six live pins into a single power source as soon as it arrives on the GPU’s PCB.”

If RTX 5070 typically have the same engineering approach, it’s possible some 5070 cards could also be pushing excessive power through a single cable, leading that cable to overheat.

Frankly, none of this seems to make much sense. The whole point of having multiple wires, surely, is to spread the load. To then engineer the connection in a manner that undermines that built-in safety factor seems pretty odd, to say the least.

It’s also a bit of a worry that it’s a 12V-2×6 power cable implicated here with its updates designed to address all those stories of melting 12VHPWR connectors on Nvidia graphics cards that date back to 2022. This is the latest power supply hardware applies to the latest GPU technology.

Of course, this could well be a very isolated incident that doesn’t imply a broader problem. But where there’s smoke in a high-performance gaming PC, the immediate culprit is not necessarily an Nvidia GPU fire, but those power cables and sockets are certainly suspect.