Today’s high-end graphics cards use up to three 8-pin connectors, which usually leads to a tangle of cables and connectors that even the best cable management sometimes struggles to organize. The next standard with 16 pins should correct all these problems.
The old Molex 6 + 2 pin connectors are therefore now technically quite simply obsolete. Nvidia has tried to solve this problem with the 12-pin Microfit connector on its latest RTX 3000 Founders Edition, but ultimately it is only a proprietary palliative solution, which does not define any new standard.
According to rumors, Next GeForce RTX 3090 Ti Would Use New 16-Pin Microfit Connector, but it is unlikely to be standard on all cards. We do not know for the moment which connector will use the next graphics cards of the American giant, but it should be very different from what we currently know. The PCI SIG would have already defined a new “High Power Connector” (H +) in the characteristics of the new PCIe 5.0 standard. It should be found in most future high-end graphics cards, here’s what it should look like according to Igor’s Lab.
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The PCI Express connector 12VHPWR
With regard to cable assignment and power specifications, the design of this connector has been specifically defined for support cards with power consumption up to 600 watts. This is therefore a major improvement over the previous Molex cables, which only reached about 150W. These 8-pin connectors were ultimately just simple 6-pin connectors, of which the other two pins are just for making sure the cable is delivering the right amount of current.
The new 12VHPWR connector is therefore not suitable for 2 × 3 and 2 × 4 PCI Express auxiliary power connectors. This is because the power pins of the 12VHPWR connector have a spacing of only 3.0 mm, while the contacts of the old 2 × 3 (6-pin) and 2 × 4 (6 + 2-pin) connectors have a greater spacing. of 4.2 mm. Figure 9-1 shows the 12VHPWR expansion card connector unplugged, and you can see two different connectors. There are twelve large pins that carry the power rail (2 × 6) as well as four smaller pins below, which are for sideband signals.
If this new Molex cable can provide so much current without immediately burning out, it is because as seen in the technical diagram below, 12VHPWR power connector provides up to 55A continuous current to power the board via a 12V power rail with a maximum power of 600W.
The PCI SIG specifies a current capacity per pin, excluding the sideband 4 pins, of 9.2A with a limit of 30 ° C rise above ambient temperature at + 12 VDC when all twelve contacts are energized. So we have a total of 55.2 amps in one direction for the 12 volt power rail, or 662.4 watts. Of course, this is a theoretical limit, so security requires that this number be lowered for security reasons. Here, we consider that 600 watts can still be guaranteed without risk, or 11% less than the theoretical limit.
The connector body must have a labeled or stamped H + sign to indicate 9.2A support per pin (or more), and its approximate location can be seen in the drawing above. It is also known that for safety reasons, the plug has a locking mechanism which must be able to withstand at least 45.00 N (approx. 5 kg) when pulled.
This connection is excellent news for future graphics cards, since in the future, a single standardized card will suffice for all the cards, provided they need an additional power connection and do not exceed a consumption of 600 watts. In the near future, you should have less trouble arranging all the cables in your towers correctly. NVIDIA is often the pioneer in its new technologies, but we do not yet know for sure whether the future RTX 3090 Ti that some leaks evoke will use this connection and will or not support the new PCIe 5.0 standard.
What about custom cables?
The availability of the various components should certainly be accessible to all enthusiasts in the near future. However, according to one manufacturer, processing is a bit more difficult than with simple Molex connectors. As a customer, you will also have to pay attention to the different sections of the cables, but not only. Indeed, with regard to the current carrying capacity of its different parts, other factors come into play in addition to the pure section of the cable.
In addition to the material used, variants with different numbers of individual strands are also of interest here. The higher the number of individual strands, the thinner the section of the individual conductors. This makes the cable much more flexible and therefore easier to lay. However, this also increases the electrical resistance and therefore reduces the maximum current carrying capacity. Below AWG 16 with a diameter of 1.29 mm (corresponds to a cross section of approximately 1.31 mm²), it is better to install nothing. The 20 amps of continuous charge capacity possible here may seem completely oversized at first glance, but the efficiency is formidable. The AWG 18 can also work if needed, but then the material should be really good, cheap alloys are therefore already excluded.
The higher requirements, especially with regard to the 4 additional signal lines, will make the task much more complicated for some amateur modders, who will probably prefer to look for another hobby or purchase additional equipment.
Source : Igor’s Lab