It all started with NVIDIA’s 12-pin connector, then 12VHPWR (12+4 pin) was released and created lots of noise, and the time has come for the 12V-2×6 which I will show you in today’s article!
Before diving for good details, I must explain PCIe CEM. According to PCI-SIG, the organization responsible for developing and maintaining the standardized approach to peripheral component I/O data transfers, Card Electromechanical (CEM) connectors are one type of PCI-SIG-developed connector. They are by far the longest-standing PCIe form factors, with the first iteration delivered in 2000. CEM connectors play a significant role, as they are the connection between a motherboard, an add-in card (AIC), and a riser card.
The fresh CEM 5.1 specification replaces the pesky 12VHPWR connector with a new one called 12V-2×6, and in this article, in a short and brief way, I will help you understand what the new connector has to offer.
Change in sense pin receptacle
The opening for the sideband pins has been increased from 1.6mm x 9.3mm to 1.75mm x 9.4mm.
Change in terminal length:
- The depth of power terminals has been increased from 4.2mm to 4.45mm (6.6mm – 2.15)
- The depth of sense pin terminals has been decreased from 4mm to 2.5mm.
Comparison of terminal differences
If sense pins lose contact, power terminals should still be fully engaged. This ensures that there won’t be any increased resistance on the connector, which can lead to problems (aka melting connectors).
Another change is the 150W setting on the sense pins. In 12VHPWR, when both sense pins are open, the maximum power is 150W. In the new connector, the open-open scenario will change to 0 watts! For the 150W setting, Sense0 has to be shorted to Sense1.
The 12+4 pin cable won’t have any changes on the PSU side IF the manufacturers and brands avoided using 12+4 pin connections on the PSU’s modular panel (something that Corsair did, for example). If they used 12+4 sockets on the PSU side, then this change will also affect this side. According to my sources, there is backward compatibility, but this is something that is not 100% confirmed yet.