Intel Alder Lake-S Is Coming, So Get Familiar With ATX12VO Power Supply Specs

ATX12VO Motherboard Connector
Intel has promised to launch its Alder Lake-S processors before the end of the year (rumor has it this will happen in November), and with it come some exciting things, such as a heterogeneous architecture, DDR5 support, and PCI Express 5.0. If things go to plan, you can also expect single-rail power supply design called ATX12VO to take hold.

What exactly is ATX12VO and why does it matter? Intel first published the ATX12VO specification in July 2019, then made a bit more noise about the standard in April 2020 when ASRock launched the industry's first ATX12VO motherboard, the Z490 Phantom Gaming 4SR (shown above, with a 10-pin ATX12VO power connector).

As the name implies, ATX12VO gets rid of the 3.3V and 5V rails, and moves the creation of those voltages to the motherboard. Why? It is more power efficient that way, and therein lies the reason ATX12VO exists—to reduce power usage, especially in light of newer energy regulations, like EPA's Energy Star for Computers v8 in 2021, the California Energy Commission Title 20, Tier 2 requirement in 2021 (and other states following suit), and Japan's Top Runner program in 2022.

"All these regulations are requiring PC makers to adjust their desktop power targets. A single rail power supply design is one answer to help OEMs reduce desktop PC idle power and meet the new government regulations," Intel explains. F"or years there have been custom single rail power supply designs. But until Intel created the ATX12VO design and publicly shared it, there was no industry standard to help PC-makers reduce the energy desktop systems use when idling."

What a power supply unit (PSU) does is take AC current from your wall's outlet and convert it to DC current that your computer can use. According to Intel, the conversion causes the greatest loss of power when your PC is at idle. Hence getting rid of the 3.3V and 5V rails on the PSU side. On the aforementioned motherboard, Intel says idle power consumption is reduced by 27 percent.

Don't worry though, your existing PSU will not become obsolete in the near future. Assuming plans have not changed, the shift to ATX12VO is primarily aimed at OEMs and system vendors.

"Intel plans to continue to publish the ATX multi-rail spec to maintain compatibility with existing motherboards and power supplies to provide the most options for our OEMs and customers," Intel told PCWorld around this time last year.

That said, it does appear Intel is making a bigger push to adopt the ATX12VO standard when Alder Lake-S arrives.

Intel Pushing To Popularize ATX12VO In Time For Alder Lake-S

Support for the newer ATX12VO standard has been relatively slow. In fact, some of you reading this may not have even heard of the specification, because there just has not been an industry-wide shift. This is one of those technologies that, if it takes off, will gradually permeate the market (sort of like USB-C).

Intel ATX12VO StatementSource: Videocardz

Forces are in motion, though. Apparently Intel is pushing for the adoption of ATX12VO with Alder Lake-S, telling its partners that motherboard vendors need around four to five months of lead time to test new designs and have them ready for Alder Lake-S. And by extension, that means OEMs and ODMs would need to be working with motherboard and PSU vendors by the end of this month, to facilitate ATX12VO in time for Alder Lake-S, which lines up with rumors that the hybrid CPU architecture will launch in November.

This is not an easy shift, though. For motherboard makers, taking on the burden of 3.3V and 5V power handling means a more complex design, a thicker PCB with more PCB layers, and perhaps a higher cost (potentially offset by PSUs coming down in price). One of the main challenges would be controlling noise on the PCB.

There are certain advantages that extend beyond lower power consumption. Moving those rails to the motherboard could be beneficial to power sensitive devices, like USB gadgets and on-board audio schemes, as well as offer better over-current and under-current protection.

So where to PSU makers stand on the shift? Notorious overclocker Roman "der8auer" Hartung spoke with several companies that make PSUs and motherboards about their plans to support the ATX12VO specification, and there are some moving pieces behind the scenes.

ASRock, for example, is readying a Z590 Pro 12VO motherboard. In addition, Seasonic said it already finished development of an ATX12VO power supply, the Focus GX650, which has been sent to Intel for certification. Once it passes, Seasonic will begin mass producing the PSU, with additional wattage options. Corsair is also working on ATX12VO power supply designs and expects to have them ready in early 2022.

Outside of ASRock, on the motherboard side, most companies are keeping mum (like Gigabyte), though ASUS did say it has a prototype board that uses the specification. Other than that, though, there's not a whole lot of confirmed information. That could be due to the nature of the spec, in that this requires close cooperation between PSU and motherboard makers.

In any event, expect to see more of ATX12VO when Alder Lake-S arrives later this year. It won't represent a wholesale industry shift, but it will be another form factor to consider.