As a reminder, 12VHPWR is the official name for the new PCIe 5.0 12+4-pin cable used on some current and upcoming high-power graphics cards and is capable of handling 600W sustained on a single cable.
You may have already seen this story covered on some rumor sites citing that the problem is with adapters converting to 8-pin PCIe connectors, but that’s incorrect and may have been based on incomplete information. Here’s what the email had to say:
“Please be advised that PCI-SIG has become aware that some implementations of the 12VHPWR connectors and assemblies have demonstrated thermal variance, which could result in safety issues under certain conditions. Although PCI-SIG specifications provide necessary information for interoperability, they do not attempt to encompass all aspects of proper design, relying on numerous industry best-known methods and standard design practices. As the PCI-SIG workgroups include many knowledgeable experts in the field of connector and system design, they will be looking at the information available about this industry issue and assisting in any resolution to whatever extent is appropriate.”
“As more details emerge, PCI-SIG may provide further updates. In the meantime, we recommend members work closely with their connector vendors and exercise due diligence in using high-power connections, particularly where safety concerns may exist.”
The PDF explains that Nvidia has been testing 12VHPWR connectors to validate that prototype power supplies and cables can meet the specification of 55A continuous. During this testing, Nvidia found certain cable routing conditions led to excess heat and, in some cases, melting.
The conditions required for the excess heat were either subjecting the cables to severe bending or a high number of mating cycles (about 40). Cables tested in these scenarios exhibited hot spots at roughly 2 and a half hours, and melting at 10 to 30 hours. Connectors from multiple suppliers have failed.
This is with a continuous 55A of current (or 660W at 12V), which would not be a typical load condition, especially not in gaming. Nvidia did not observe any failures on connectors with low mating cycles and without any bend.
die haben doch echt was am Helm.
