The Peripheral Component Interconnect Special Interest Group (PCI-SIG) is the standards body that writes specifications for major system interconnects, including PCIe. Last year, the group developed and approved a new standard designed to predict the future power consumption of high-performance GPUs: the 12VHPWR interface for PCIe 5.0 devices.
The 12VHPWR has begun to replace some sort of 8-pin Molex connector in the latest computer power supplies. It can deliver 600W of power through 12 rails, four times the power of the 8-pin connector. It is the same size as the boot 8-pin.
PCI-SIG is happy with the 12VHPWR standard – that’s not the problem. The problem is the cheap 8-pin to 12VHPWR adapters that vendors are starting to bundle and sell with some power supplies. Foreign tech media outlet Wccftech reports that the organization sent the following information to its members last week.
"Please note that the PCI-SIG has recognized that certain implementations of 12VHPWR connectors and components have exhibited thermal variations that can lead to security issues under certain conditions. While the PCI-SIG specifications provide the necessary information for interoperability, they do not attempt to cover all aspects of proper design, relying instead on many of the industry's best known methodologies and standard design practices. Since the PCI-SIG working groups include many knowledgeable experts in the field of connector and system design, they will look at the available information on the industry's issues and, to the extent appropriate, assist in resolving any problems. The PCI-SIG may provide further updates as more details become available. In the meantime, we recommend that members work closely with their connector suppliers and exercise due diligence when using high power connections, especially where there may be security issues."
In a cryptic manner, the organization said that certain components could melt or catch fire in the most extreme cases if they could fail in harsh environments, such as high-temperature housings.
Wccftech speculates that the problem stems from the variable nature of the 8-pin connector. Many current generation GPUs require multiple 8-pin ports, and even then, they often exceed the rated limits of these connectors. Sometimes the GPU draws most of its power from a single plug, putting an unnecessary burden on it.
In a quick test, Wccftech used an adapter to connect two 8-pins to a single 12VHPWR connector and placed them under a 600W load. The power supplies easily delivered 600W by transferring just over 300W per 8-pin, even though they were only rated at 150W.