To further improve PC performance in terms of both efficiency and safety, a new revision to the ATX PSU specification has recently been announced in the form of ATX 3.1. In this article, we will go over ATX 3.1 performance and features, and the unique benefits of Cooler Master’s own ATX 3.1 products.

What changes does ATX 3.1 bring?

All the most significant changes represented by ATX 3.1 exist in the introduction of the 12V-2x6 power connector, a new connector specification developed to replace ATX 3.0’s 12VHPWR connector which reportedly experienced some issues under heavy workloads with high-end graphics cards.

But first, let us clarify the naming:
• The older cable type used in ATX 3.0 is referred to as 12VHPWR, an abbreviation for 12 Volt High Power.
• The new cable type used in ATX 3.1 is named 12V-2x6, which stands for 12 Volt 2 rows of 6 pins.

The new 12V-2x6 power connector is fully compatible with the 12VHPWR connector. In essence, the new 3.1 connector appears almost identical, is fully interchangeable, and can perform all the functions of the old connector, but with enhancements in safety and efficiency. Specifically, the power pins have been extended by 0.25mm to enhance connection reliability by enlarging the contact surface area and reducing temperatures. Additionally, the signal pins have been shortened by 1.5mm to ensure users have an easier time fully plugging in the connector to achieve the safest, most reliable connection.

As detailed in new Intel’s ATX 3.1 specifications, once the cable is connected with GPU pins “Sence 0” and “Sens 1” it will be short-circuited by the GPU internally. That will send a signal to a PSU that the connection is secure and tight, and the GPU is ready to receive the power.
Whereas with older ATX 3.0 these pins being open means that the connection between PSU cable and GPU does not have to be tight. Overheat was often the result of such a connection, casting a danger for a PC build.

Two power modes are also being introduced with the 12V-2x6 power connector, 150W, and 300W, providing more lower-end power options in addition to the 450W and 600W modes.
Each of these changes ensures that the 12V-2x6 power connector improves upon all the shortcomings of the 12VHPWR connector while providing several performance and reliability improvements. Additionally, the version of the PSU cable and GPU power connectors can simply be identified in the following way:
- 12VHPWR (old type) connector is labeled “H+”.
- 12V-2x6 (new type) connector is labeled “H++”.

H+ and H++ connectors and cables are compatible with one another and will work well. However, by combining H+ with H++ cable you will not receive all the additional safety benefits that ATX 3.1 brings. Specifically, combining H+ and H++ loses the tighter connection provided by using only H++ connectors.

Cooler Master’s ATX 3.1 implementation and improvements

At Cooler Master, we have already begun updating some of our PSUs to feature ATX 3.1 compatibility. Each of our ATX 3.1 PSUs will feature the enhanced connectors as described above, allowing for improved durability and lower overall temperatures.

The reason why there is so much attention given to the safety of the new 12V-2x6 cable is due to the overheating issues that some users encountered with the older 12VHPWR cable. This overheating problem often stemmed from the cable being bent, which increased electrical resistance along the bent section and reduced the contact surface area of the connector pins. To address this safety concern, Cooler Master has designed its connectors with a 90-degree angle; drastically reducing the strain placed on the cable. This design has already been implemented on our current 3.0 cables and will continue to be used on upcoming ATX 3.1 PSU cables as well.

Additionally, our 90-degree 12V-2x6 connectors include improvements such as increased flexibility, 4 springs for a larger contact area with lower impedance, and a 25% thicker terminal. Each of these improvements means that our connectors have a 45% lower impedance change rate, a 12% higher average insertion/withdrawal force, and 5°C lower temperatures.

Cooler Master PSU series that will soon support ATX 3.1:

X Silent Edge Platinum
X Silent MAX Platinum
X Mighty Platinum
V Platinum V2
MWE Bronze V3 (soon to be released)
G Gold V2 (soon to be released)
GX II Gold
V SFX Platinum
V SFX Gold
MWE Gold V2


Given the improvements that ATX 3.1 brings to the table, it is a good time to prepare for upgrading your build to work with the new spec. For help with planning a build and figuring out how much wattage you’ll need, check out our PSU calculator.

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