Since Wednesday, the GeForce RTX 4090 has been commercially available as a Founders Edition (test) and as a custom design. The first customers already have the graphics card, and many will follow today and over the weekend. ComputerBase once again clearly explains how it can be connected to the power supply via the 12VHPRW plug.
1. Case: old power supply with included adapter
Each GeForce RTX 4090 comes with an adapter from the new 16-pin connector (12VHPWR, 12 Volt High Power) to 4 × 8 pins. This adapter can be used to connect the GeForce RTX 4090 to any power supply that has at least three 8-pin connectors. The graphics card will not start with only two 8-pin connectors on the adapter!
If you connect three 8-pin cables, you cannot increase the TDP of the graphics card to over 450 watts, because the adapter signals the maximum limit permitted by the PCIe standard (3×8 pins correspond to 3×150 watts = 450 watts) via the Sense pins and the driver adapts to them. If you connect four 8-pin cables, you can (depending on the model and setting) use up to 600 watts (4×150 watts = 600 watts possible).
Power supplies that have three or even four 8-pin cables should usually be powerful enough to be able to deliver the electrical power required by the graphics card. Nvidia recommends a power supply with at least 850 watts to operate the GeForce RTX 4090, whose TDP is limited to 450 watts as a Founders Edition.
Many power supplies offer 2×8 pins in one strand, so all four sockets of the adapter can be operated from two strands. In this case, however, customers should make sure that the plugs on the Molex High Current Terminals cable and the cables are designed according to 16AWG and not just 18AWG in order to avoid overheating under continuous load as a result of too small cable cross-sections – after all, every terminal could or cable when utilizing the maximum possible TDP of 600 watts, 300 watts at 12 volts and thus 25 amperes flow permanently.
2nd case: Old power supply with new 12VHPWR cable
Alternatively, more and more power supply manufacturers are offering 12VHPWR cables for certain existing series in the accessories or spare parts trade. Depending on the design, these are connected to two or three PCIe terminals of the power supply unit and can then usually deliver up to 600 watts to the graphics card. This is signaled accordingly via the 4 sense pins on the connector.
In this way, the stiff adapter from the scope of delivery can be replaced by a relatively slim 12VHPWR cable that has not yet been sleeved.
3. Case: An (ATX 3.0) power supply with 12VHPWR ex works
The third alternative is to connect the graphics card to a power supply that is already equipped with 12VHPWR ex works. These models are based on both the old ATX 2.x and the new ATX 3.0 standard.
ATX 3.0 power supplies have the advantage that this standard was explicitly designed for the specifications of the 12VHPWR connector, which is part of the PCI Express 5.0 standard. This means that the fact that officially short-term peak loads of up to three times the average (i.e. 1,800 instead of 600 watts) can occur over 12VHPWR was taken into account. However, Nvidia probably designed the GeForce RTX 4000 series with the knowledge that it is mostly operated with ATX 2 power supplies, so the purchase of an ATX 3.0 power supply is not necessary.
The following content provides more details on the subject of 12VHPRW cables and the ATX 3.0 standard:
- 12VHPWR connector: Overloaded connector also possible without adapter
- New 12VHPWR connector: be quiet! for power supply compatibility with RTX 4000
- 12VHPWR connector: Seasonic and FSP with cables and power supplies
- ROG Loki SFX-L 850 W: Asus' first ATX 3.0 power supply with 80Plus Platinum is tiny
Finally, a question for everyone who already owns a GeForce RTX 4090: How is it in this one If the connection is made? Or how do those who have ordered or are considering an RTX 4090 plan to connect the graphics card?
How do you put the RTX 4090 into operation?
- Via the included 16-pin to 4×8-pin adapter
- Via a 12VHPWR adapter cable from the power supply manufacturer
- Via the 12VHPRW cable already present on the power supply
- Abstention (show result)
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