16-Pin Power Connector Gets A Much-Needed Revision, Meet The New 12V-2×6 Connector
Owners of graphics cards with a 16-pin (12VHPWR) power connector need fear no more. According to a new report from a German publication, Igor’s laboratory, PCI-SIG is revising the specification to save the 12VHPWR) power connector. With multiple user reports of melted 16-pin connectors on Nvidia’s GeForce RTX 4090, one of the best graphics cards for gamers, it’s time for PCI-SIG to take action on the issue. .
Innovation is great because it encourages companies to release novel products. However, too much innovation is also bad. When news broke that Nvidia would feature 16-pin power connectors on some of its consumer GeForce RTX 40 series (Ada Lovelace) graphics cards, feedback was mixed. Some are happy to finally get rid of cable clutter and instead of three 8-pin PCIe power cables, he can now use a single 16-pin power cable. However, some have expressed concerns about NVIDIA’s decision. 12VHPWR is a new connector and there is always some trepidation for early adopters. In addition, many users were concerned about the amount of power flowing through that tiny 16-pin power connector.
Unfortunately, the GeForce RTX 4090 took a lot of casualties before upper management realized the 12VHPWR power connector deserved a revision. Igor’s Lab has shared a short excerpt from the draft of the upcoming CEM 5.1 specification that will form the basis of the ATX 3.1 standard. The 12V-2×6 power connector replaces the 12VHPWR power connector. Reportedly named “PCIe Base 6.0,” the draft explicitly defines the maximum and sustained power measurement guidelines for connectors.
The previous 12VHPWR power connector had a maximum power of 600 W, 525 W from the connector, and 75 W from the expansion slot. On the other hand, the new limits for 12V-2×6 power connectors are 675 W max, 600 W at the connector side and 75 W from the expansion slot. The two power connectors are obviously different. However, the PCI-SIG has made efforts to help inexperienced users distinguish between users by using unique identifiers. Older 12VHPWR power connectors have the H+ marking, while newer 12V-2×6 power connectors have the H++ identifier.
image 1 of 3
The 12V-2×6 power connector provides up to 55A power for graphics cards up to 600W on the 12V AUX rail. The guidance states that the current pin minimum rating is 9.2A per pin with 12 contacts active, with an upper limit of T rise of 30 degrees Celsius above ambient at 12V DC. The connector must have an H identifier to indicate that it supports up to 9.2A or more per pin.
The uneven contact resistance of the cable can cause the pins to show currents in excess of 9.2A. However, the total current he must not exceed 55A RMS in either direction. Manufacturers must ensure that connector assemblies containing 16 AWG wires and pins meet minimum current requirements and maximum temperatures. The document also specifies a retention force for the locked connector, emphasizing a minimum of 45N when pulling the connector axially.
image 1 of 3
The 12V-2×6 power connector holds the same number of contacts as the 12VHPWR power connector. The 12 large contacts supply power and the 4 small contacts are sideband signal sense pins. However, PCI-SIG made significant changes to the 12V-2×6 headers (sockets) and connectors (plugs).
On the 12VHPWR header, the sense pins were 4mm long and 0.45m apart from the edge. The target contact is 3 mm behind the edge of the aperture. The 12V-2×6 header shares similar dimensions with the 12VHPWR header. The sense pin target contact is also the same (3mm) to maintain compatibility. For safety reasons, PCI-SIG extended the tip-to-edge spacing of the sense pins to 1.7mm on the 12V-2×6 headers, an improvement of 1.25mm. As a result, the pin behind the tip is 2mm behind the outer edge.
The Sense0 and Sense1 contacts are important for proper operation of the 12V-2×6 power connector. If Sense0 and Sense1 are left open, the graphics card will not be powered. Conversely, grounding Sense0 and leaving Sense1 open allows up to 300 W, and grounding both contacts allows up to 600 W. Conversely, the 150W configuration means connecting Sense0 and Sense1 directly without ground. Igor’s Lab believes the 150W design will require a new power cable or special power supply.
Shortening the sense pins sounds like something PCI-SIG should have done with the 12VHPWR power connector from the beginning. If the connector is not fully inserted into the header, the graphics card will not power on. Also, if the connector is accidentally unplugged, the graphics card will power off. In a way, the pins are placed deeper in the pin chamber, ensuring that the connector is fully mated.
image 1 of Four
Logically, the 12V-2×6 power connector or adapter features a slightly different design than the existing 12VHPWR power connector. According to the draft, there could be two variations of the 12V-2×6 power connector. Option 1 has a 0.7 mm thick shoulder below the sense pin, while option 2 has no shoulder. Regardless of design, both variants have the same dimensions. But there is no explanation behind the reasons for his two proposed options.
The recommendation to bend the cable when too close to the connector still applies to the 12V-2×6 power connector. Previously, the recommended spacing for 12VHPWR power connectors was at least 35mm from the connector before bending, but some power supply vendors recommended up to 40mm as a good dimension. However, the distance of the 12V-2×6 power connector is unknown, as Igor’s lab did not provide specific measurements in their report. The 12V-2×6 document also details more technical aspects such as test methods.
Another interesting piece of information in the draft concerns the temperature of the pins of the 12V-2×6 power connector. Temperature life is 168 hours at 105°C, but with preconditioning the expected value is 92 hours at 105°C. Therefore, manufacturers should consider thermal limits when designing graphics cards to ensure that other components such as shunts, VRMs, and coils do not add unnecessary heat to the header.
Specifications for the 12V-2×6 power connector are not final. However, Igor’s Lab believes they are unlikely to change. However, the fact that a vendor can spec his 12V-2×6 power connector for 150W or 300W might mean that we might find new power connectors on lower-end graphics cards as well.
Everything looks fine on the drawing board until it hits the market, but then things start to go wrong here and there. The same was true for the 12VHPWR power connector. Only time will tell if the PCI-SIG fix will yield good results.
