Does The 12VHPWR Connector Really Wear Out After 30 Mating Cycles?

February 23, 2025 by Maya Posch 50 Comments

When PCI-SIG introduced the 12VHPWR power connector as a replacement for the 6- and 8-pin PCIe power connectors, it created a wave of controversy. There were enough cases of melting GPUs, PSUs, and cables to set people on edge. Amidst this controversy, [JayzTwoCents] decided to do some scientific experimentation, Mythbusters-style, specifically: do these 12VHPWR (or the 12V-2×6 successor) wear out upon hitting the often cited 30 mating cycles? If this is the case, it could explain why people see wildly different current loads between the wires in their GPU power cables. Perhaps reviewers and hardware enthusiasts should replace their GPU power cables more often.

Like many Mythbuster experiments, the outcome is less than clear, as can be observed in the below graph from one data set. Even after 100 mating cycles, there was no observable change to the contact resistance. One caveat: this was only performed on the GPU side of the connector. The first cable tested was a newer connector type that uses a single-split leaf spring design. Initially, most of the 12VHPWR connectors had a double- or triple-dimple design to contact the pin, so [Jayz] tested one of these, too.

The amazing thing with the 2022-era cable that got pulled new out of packaging and tested was that it looked terrible under the microscope in terms of tolerances and provided a very uneven load, but it got better over time and also lasted 100 cycles. However, it must be said that ‘lasted’ is a big word here, as the retention tab wore off by this point, and the connector was ready to fall out with a light breeze.

Perhaps the ‘mating cycles’ specification is more about the connector as a whole, as well as how the connector is (ab)used, at which point good (long-term) contact is no longer assured. Along with the different types of Molex Mini- and Micro-Fit style connectors, it’s worth keeping an eye on with more applications than just GPUs.

We have certainly seen some burned connectors. Particularly in 3D printers.

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showing the connector after its torn down from the side of the wire solder points, showing how thin are the metal pads, and also that one wire has already broken off

NVIDIA Power Cables Are Melting, This May Be Why

October 28, 2022 by Arya Voronova 57 Comments

NVIDIA has recently released their lineup of 40-series graphics cards, with a novel generation of power connectors called 12VHPWR. See, the previous-generation 8-pin connectors were no longer enough to satiate the GPU’s hunger. Once cards started getting into the hands of users, surprisingly, we began seeing pictures of melted 12VHPWR plugs and sockets online — specifically, involving ATX 8-pin GPU power to 12VHPWR adapters that NVIDIA provided with their cards.

Now, [Igor Wallossek] of igor’sLAB proposes a theory about what’s going on, with convincing teardown pictures to back it up. After an unscheduled release of plastic-scented magic smoke, one of the NVIDIA-provided connectors was destructively disassembled. Turned out that these connectors weren’t crimped like we’re used to, but instead, the connectors had flat metal pads meant for wires to solder on. For power-carrying connectors, there are good reasons this isn’t the norm. That said, you can make it work, but chances are not in favor of this specific one.

The metal pads in question seem to be far too thin and structurally unsound, as one can readily spot, their cross-section is dwarfed by the cross-section of cables soldered to them. This would create a segment of increased resistance and heat loss, exacerbated by any flexing of the thick and unwieldy cabling. Due to the metal being so thin, the stress points seem quite flimsy, as one of the metal pads straight up broke off during disassembly of the connector.

If this theory is true, the situation is a blunder to blame on NVIDIA. On the upside, the 12VHPWR standard itself seems to be viable, as there are examples of PSUs with native 12HPWR connections that don’t exhibit this problem. It seems, gamers with top-of-the-line GPUs can now empathize with the problems that we hackers have been seeing in very cheap 3D printers.