With the next generation launching soon, power adapters are one of the main components that users may want to upgrade for their PCs. This is due to the introduction of new requirements and standards to provide sustainable and clean energy and avoid issues related to transit altitude and powered flight. While there are many manufacturers that bundle Gen 5 (12VHPWR) connectors with existing power supplies, investing in a true ATX 3.0 compatible power supply is a much better option for this reason.
For this reason, you should get an ATX 3.0 compatible power supply with the correct Gen 5 (12 VHPWR) connectors.
PSU manufacturers are gearing up for a major product launch New ATX 3.0 designBut there are also some manufacturers that bundle existing ATX 2.0 power supplies with Gen 5 connectors. As expected, the upcoming graphics cards will be really power-hungry and require up to 600 watts of power.
What is a 12VHPWR connector?
The 12V HPWR auxiliary power connector is designed to deliver up to 600W directly to additional PCIe* cards. This power connector is not compatible with existing 2×3 or 2×4 auxiliary power connectors. The power pins on the 12VHPWR connector are 3.0mm apart, while the contacts on the 2×3 and 2×1 connectors are 4.2mm larger. The 12V HPWR auxiliary power connector has twelve large contacts for power transmission and four small contacts on the bottom for sideband signal transmission.
ATX 3.0 12VHPWR Connector Specifications
The performance requirements for conductors are as follows:
- Power Supply Pin Current Rating: (excluding sideband contacts) 9.2A maximum T-rise per pin/position above ambient temperature conditions of 30°C = at 12VDC when all twelve contacts are active. The body of the connector should have an embossed H+ label or letter indicating 9.2A/pin or higher support. Note the approximate location of the marker on the 12VHPWR (R/A) right angle PCB header.
ATX 3.0 Gen 5 vs ATX 2.0 Gen 5, what’s the difference?
To achieve the 600 W power requirement, graphics cards are equipped with either one PCIe Gen 5 header (12 VHPWR) or three 8-pin headers. If you’re using an existing ATX 2.0 power supply, your only options are to use a Gen 5 adapter or three 8-pin connectors to boot your card. With an ATX 3.0 power supply where the Gen 5 connector comes from the main unit, you don’t have to worry about adapters because it will connect directly from the power supply to the graphics card.
Now, I’m told by most manufacturers that using a standard 8-pin to 12V HPWR converter should work fine, but according to PCI-SIG, this is not the case. As you can see, the 12VHPWR Gen 5 connector is rated for loads up to 600 watts, while the 8-pin connector is rated for a maximum load of 150 watts. This is where security risks come into play.
The following is an email forwarded PCI-SIG notice regarding security vulnerabilities associated with the use of Gen 5 non-ATX 3.0 compatible power supplies:
Dear PCI-SIG Member,
Please note that PCI-SIG has recognized that some applications of 12V HPWR connectors and assemblies exhibit thermal variations that may cause safety issues under certain circumstances. Although the PCI SIG specification provides the necessary information for interoperability, it does not attempt to cover all aspects of proper design because it relies on many well-known industry methods and standard design practices. Since the PCI-SIG working groups include many experts in the field of connector and system design, they will consider the available information on the industry and provide appropriate assistance in any solution.
PCI-SIG may provide further updates as more details become available. In the meantime, we encourage members to work closely with connectivity providers and exercise due diligence when using high performance connectivity, especially where security concerns exist.
thanks,
The mail clearly states that there are security vulnerabilities related to the PCIe Gen 5 connector that showed thermal drift in a private PCI SIG test. We wanted to get to the bottom of this problem and find out what caused it in the first place, and that’s what we did in the following test results.
Real tests show insufficient load balancing with 5G inverters
So to find out the heat and, more importantly, the performance disparity between a single Gen 5 connector and a 3x 8-pin to Gen 5 adapter, we used an existing Gen 5 power supply from a leading power supply manufacturer. A 600W load environment is set up and a Gen 5 adapter is used with a 12V HPWR connector on one end and two 8-pin connectors on the other. The 12VHPWR connector connects to the GPU while the two 8-pin connectors connect to the inside of the power supply.
The two 8-pin connectors each provide a maximum power of 25 amps, or about 300 watts, which is twice the maximum power of 150 watts. Here, PCI-SIG states that the thermal difference is not only due to the high power flowing through the 8-pin connectors, but also a problem with load balancing through the transformer.
In the second test, we set up a 450W test load with an NVIDIA GeForce RTX 3090 Ti graphics card. Here we used the reference adapter that came with the card and the 12VHPWR to 3x 8-pin connector. Here, instead of sharing the load equally across the three conductors, one 8-conductor conductor carries 23.5 amps or 282 watts, while the remaining conductors draw 6-8 amps (80-100 watts). That means even if you use three sockets, there is still a safety issue with a single 8-pin connector.
Some transformer cables that use better materials like copper alloy can allow more than 7 amps per pin, 21 amps from three pins, but still no one can guarantee stability and safety for long usage, especially 3x power trip.
A Gen 5 connector can handle up to 55 amps, so that’s under 600 watts (50 amps), and the ATX 3.0 standard it’s built on can handle 3x transient spikes. The details of the two tests are as follows:
12V HPWR connector with 2 x 8-pin adapter at 600W load test:
- 1 x 8-pin connector = 25.4A or 304.8W (2x increase over 150W rating)
- 1 x 8-pin connector = 25.1A or 301.2W (2x increase x over 150W)
12V HPWR connector with 3 x 8-pin adapter at 450W load test:
- 1 x 8-pin connector = 25.34A or 282.4W (88% increase over 150W rating)
- 1 x 8-pin connector = 7.9A or 94.8W (within 150W rating)
- 1 x 8-pin connector = 6.41 or 76.92 watts (within 150 watts rating)
Using a Gen 5 connector directly from an ATX 3.0 power supply will not cause temperature or power differences as the cable is rated for high loads of up to 600 watts over a single wire. This may not be a concern now, but with the triple power peaks we’ve come to expect from next-gen graphics cards (1800W ~ 600W x 3), this can cause overcurrent and negate the benefits of your PSU. This causes a power outage and shuts down computers when they hit a power wall. Therefore, it is best to invest in a Gen 5 and ATX 3.0 compatible PSU to ensure your PC runs smoothly. We will provide an update on this as we receive more information from the manufacturing community at PSU and PCI-SIG.
Summary:
- The 12VHPWR connector is rated for 600W
- The 8-pin connector is designed for 150 watts.
- Under 600W/450W load, more than 150W will be delivered through 8 pins
16-pin to 2×8-pin splitter cable connector. - Current is not well balanced in 16 pin to 3×8 pin splitter cable.
- Original 12VHPWR connector for high performance needs like graphics
cards
However, if you are planning to build a new gaming PC with an RTX 4090 or an RX 7900 XT, make sure you get a power supply within the corresponding wattage range in the ATX 3.0 standard. Currently, many power supply manufacturers prefer MSIAnd come onAnd GBAnd FSP Group ThermaltechAnd seasonalAnd Silberstein And cold head They announced their PCIe Gen 5 and ATX 3.0 compatible designs.
