ATX12VO Tested - The Future of Power Supplies?
Published: 27th January 2021 | Source: OC3D Internal Testing | Price: |
Complications - New connectors, SATA power and other voltages
When looking at our High Power HP1-P650GD-F12S power supply, it is easy to believe that this is just a normal ATX power supply. This looks like a normal ATX power supply, but it is very different under the hood.
This power supply only delivers 12-volt power. Gone are the 3.3V and 5V rails that you see in most other ATX power supplies. In many ways, this power supply is simplified, cutting away unnecessary baggage to create a PSUs that are more efficient and cheaper to produce. All of High Power's engineering expertise is focused on delivering efficient 12V power, but with that power comes new connectors and a lot of confusion for long-time PC builders.
Where's my 24-pin cable and what happened to my SATA power connector?
As we have said before, this power supply is 12-Volt-Only. This PSU is not compatible with normal motherboards and other components. Instead of a 24-pin connector, ATX12VO power supplies use a smaller 10-pin connector, though the eagle-eyed amongst you will notice that one of these pins are unoccupied.
Looking at the Molex and SATA connections below, you will also see that the 3.3V and 5V pins of these connectors are gone, making these connectors useless for devices that need 5V or 3.3V power. Many devices like fan controllers and water cooling pumps only require 12V power, and that's what these 12V-only connectors are for. To connect SATA-powered HDDs and SSDs, you will need a new connector...
SATA power from your motherboard?
To deliver 3.3V and 5V power, ATX12VO systems will derive these voltages from 12V using ICs on their motherboards. This means that SATA power for SSDs and similar devices will come from your motherboard, not your power supply.
This design decision means that motherboard makers will need to supply enough SATA power ports on their motherboards to utilise all of their SATA ports. Below is a picture of the ATX12VO standard's 4-pin to dual SATA connector, which must be plugged into your motherboard.
On our ASRock Z490 Phantom Gaming 4SR, the motherboard has 4 SATA data connections and two 4-pin SATA power plugs. These SATA power connectors can be used to power two SATA drives each.
Instead of a traditional 24-pin, our ASRock Phantom Gaming 4SR uses the following connections for power. First, we have ATX12VO's new 10-pin connector, and next to it we have a 6-pin PCIe power connector for supplemental power. Beside that, we have a 4-pin motherboard-to SATA power plug connected.
With an ATX12VO power system, processors will still be powered by ATX 4-pin and ATX 8-pin power connectors, and graphics cards will still be powered by 6-pin and 6+2-pin PCIe power connectors. These connectors only use 12V power and therefore, do not need to be modified to be used with ATX12VO power supplies.
12V to 5V/3.3V conversion on your motherboard?
Below you can see the power circuitry required to translate 12V power to 3.3V and 5V power on ASRock's Z490 Phantom Gaming 4SR motherboard. Between the motherboard's memory slots and power connection points are DC-to-DC ICs used to create 3.3V and 5V power for the devices that need it. This will include your PC's USB ports, SATA-powered devices and some PCIe devices.
Intel has claimed that these new power circuits will not make motherboard much larger than they are today and that ATX12VO motherboards that are MATX and smaller in size are possible. OEM motherboard designers are already working around these issues with custom 12VO systems, making this a design challenge that can be overcome with relative ease.