The latest development in the Nvidia GeForce RTX 5080 and 5090 12VHPWR connector meltdown issue sees a microscope analysis reveal that the manufacturing and certification process of the 12VHPWR cables and connectors may be at fault for recent power and current imbalances and dead GPUs. https://www.notebookcheck.net/Apparent-12VHPWR-cable-manufacturing-defects-add-to-RTX-5000-series-design-changes-as-root-cause-for-melting-power-connectors.961033.0.html
This article is absolute nonsense.
It says cables designed to the newer spec are better... There is no change to the cable in the new spec, the change is to the sockets only.
Also it's been shown the issue is with the lack of load balancing ability in the GPU that is causing the issue.
Quote from: JM on February 16, 2025, 10:35:32This article is absolute nonsense.
It says cables designed to the newer spec are better... There is no change to the cable in the new spec, the change is to the sockets only.
Also it's been shown the issue is with the lack of load balancing ability in the GPU that is causing the issue.
Actually both of those statements are false. Multiple cable manufacturers have gone on record to state that there are differences between the 12VHPWR cables and the 12V-2x6 cables. MODDIY was the latest one to state this and only recommends the 12V-2x2 cables for the 50 series. Nvidia confirmed this by pointing Tech Radar to that very quote when they asked for a statement from Nvidia.
The lack of load balancing on the card isn't the CAUSE of the issue, it's what's allowing the cable to melt instead of just turn off when one or more of the pins isn't making good contact. The issue is still imbalanced load caused by poor pin contacts. So, you can call the lack of extra shunt resistors a second point of failure, but it is certainly not the root cause of the issue.
Faulty spec. Outside the computer, eletrical specs are REQUIRED to have generous margins so if things are not precisely in spec you don't have your connectors melt. (This is why you don't have your electrical outlets melt every time you don't carefully make sure the plug is tight, fully inserted, in brand new condition, and then double check all that.).
The wire gauge and metal to metal contact in these connectors and plugs is about half of what would be required if it followed the same rules required for electrical connectors outside the computer. (So, if you had that margin so you had a connector spec'ed for 18 amps a pin instead of like 9... 22 amps would still be out of spec but not by nearly as much so you'd be unlikely to get these meltdowns. That's precisely why most electrical stuff has these margins, to be honest.)
Sigh
These are simply Molex Minifit connectors and housings.
Within the Minifit family, there are a number of DIFFERENT pin part numbers for different gauge wires as well as pin finish/plating options.
As with just about ANYTHING that has been around for DECADES, many 3rd parties also make SIMILAR pins and housings that look the same.
However with the above said, improper gauge wire and/or crimps and/or insertion of pins into said connector even IF pins have proper contact area and metal thickness & materials can cause problems.
IMHO: drawing 18A from a connector with 6x 9A rated pins ought not be an issue.