With the GeForce RTX 3000 graphics, Nvidia invented the use of a new 12-pin power connector instead of the classic 8-pin PCIe connectors, which it later standardized within ATX 3.0 and PCIe 5.0. This connector carries larger currents (and thus supplies more watts) and usually only one is enough for graphics, but it is significantly more subtle and, as it turns out, more prone to problems. Now a different connector is supposed to replace it, but in reality it is only a small change.
From the beginning, igor’sLAB website followed the arrival of the new connector marked 12VHPWR and eventual problems with its insertion and rather dangerous failure, when the connector was destroyed and the card was damaged by overheating. Now he came with the news that the ATX 3.1 standard and Nvidia will at least formally abandon it. According to the currently working version of this new standard, instead of the 12VHPWR connector, the connector marked 12V-2×6 described by the CEM 5.1 specification should be used. Along with the ATX 3.1 standard (which concerns power supplies), the latter is also supposed to codify the PCI Express 6.0 standard.
On closer inspection, however, it appears that this is not actually a replacement, and certainly not a course change.
12VHPWR v2 12V-2×6
The new 12V-2×6 connector is very similar, and one could almost say the same. The physical design is the same, and even compatibility should be maintained. The difference is that the four auxiliary pins on the connector used for signaling between the GPU and the source have been modified. We are talking about the connector on the side of the card, i.e. in the port where the cable connector is inserted.
The 12V-2×6 connector / port has these pins shortened by 1.7mm. Why? It causes them to be linked a bit later when inserted. The GPU should only start drawing current when these pins are connected. The shortening is to ensure that the user properly inserts (all the way) the entire connector, because otherwise the signal wires will not come into contact and the GPU will not start. Insufficient insertion of the connector, and thus poor contact of the power pins, was apparently responsible for the incidents where the connectors burned and melted. Or at least for the majority of cases – but of course the question is whether there is a mistake from the beginning in that the entire proposal does not have a large enough reserve for such cases.
Various changes and drawings to this connector you can see on igor’sLAB.
Renaming due to bad reputation
You may recall that the idea of shortening the signal wires and thereby forcing more thorough insertion of the connectors is not new. The fact that Nvidia came up with this modification, which is supposed to improve the reliability of the 12VHPWR connector, appeared already last year, and this change was supposed to be prepared with the PCI-SIG consortium. It appears that instead of this design being accepted as a revision of the 12VHPWR connector, the new version of the connector was simply renamed “12V-2×6”. The plastic of the connectors should be different – the old version 12VHPWR should have a molded H+ marking, the new version incremental H++ instead.
Quite possibly, the actors are trying to cut off the bad reputation of the 12VHPWR connector for reputational reasons, so that this style of power supply is no longer associated with previous problems. From a certain point of view, this is not exactly fair, because the small dimensions and subtlety of the connector are preserved, so part of the factors, the combination of which problems arise, remain here.
The modified connector has already appeared on the RTX 4070 unnoticed
The new 12V-2×6 connectors should work in old graphics and vice versa, so the changes are not such that compatibility is broken. Physical modification with shorter pins can even be present on power supplies and adapters, which will still be marked as ATX 3.0 / 12VHPWR. It even seems that Nvidia has already started using such a connector (port) and it already appeared on the GeForce RTX 4070 Founders Edition, but no one noticed it at first.
GeForce RTX 4070 Founders Edition
Author: Nvidia
On the other hand, according to igor’sLAB, with the renaming of the connector, in addition to the safety fuse with pin shortening, some other specification changes should be made, where the requirements for the quality of the connectors are to be tightened, which should hopefully improve overall reliability.
On the contrary, it appears that both NTK-type power wire contacts and Astron-type contacts, which have multi-point pin-to-sleeve contact and are considered more prone to problems and overheating, will continue to be allowed.
The connectors must handle a minimum current of 9.2 A per pin, and when operating all pairs of wires in a 12-pin connector, the temperature must rise by a maximum of 30 degrees against the ambient temperature. The entire cable and connector must not exceed a load of 55 A and the connected and secured connector must withstand a force of at least 45 N in axial tension. But it must be said that the 12VHPWR has problems more with forces acting in the direction of the sides, which can disturb the uniformity of contact and resistance and lead to overheating.
However, the connector also increases the power limit for the cards. For CEM 5.0/12VHPWR, it was prescribed that a maximum of 600 W can go through the cable, but the consumption of the card can also only be a maximum of 600 W. For the CEM 5.1/12V-2×6 specification, the maximum for the cable is also 600 W, but the card can go up to 675 W (when the PCIe x16 slot adds 75 W).
Caution is always in order
In any case, the new 12V-2×6 connector will still have to be handled with care, just like with the 12VHPWR connector. It will be necessary to be careful that the cable behind the connector does not bend too much and that its routing in the box does not act on the connector with any forces that would “like” it to the sides. And of course it will be good to keep an eye on the complete insertion, although there should be less room for error in this matter.
It is probably still a good idea to check these small connectors carrying large currents more often (after installation and sometimes as a precaution) whether they are hot during operation or show signs of heating, such as deformation, changed color and the like.
2023-07-07 04:07:08
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