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Report: 12V-Only Power Supply Spec Launching This Year

(Image credit: Shutterstock)

The current ATX power supply specification has been quite consistent since about 1995 with but a few changes since. However, that might change soon, according to CustomPC. The site reported that Intel will launch its "ATX12VO" design specification, with the "O" standing for "Only," this year. 

Initially, the transition will only hit system integrators, so the DIY space will likely continue using the existing 12V ATX design for quite some time.

The idea behind ATX12VO is that it ditches the 3.3V and 5V rails, leaving the power supply's only job as to provide 12V to the system's components. This simplifies the power circuitry design and, thus, lowers the production cost of components.

This change isn't surprising, as many devices can make do with 12V only, and many power supply designs operate with a single big 12V rail that uses a simple step-down DC-DC converter to provide 5V and 3.3V to the components that do still need it. These components include hard drives, SATA-mounted SSDs and most USB devices. 

Many of the pins on the current 24-pin ATX connector are redundant by today's standards, and a lot of modern systems don't need SATA hard drives or SSDs anymore now that NVMe M.2-based SSDs are gaining popularity. Moreover, various USB devices are also slowly starting to adopt 12V as their input voltage to speed up charging, and chances are that there will be a day when all new USB devices are built on using 12V rather than 5V. 

Expected 10-pin ATX12VO motherboard power connector design. (Image credit: CustomPC)

For the motherboard connectors that do remain, the replacement is said to be a 10-pin connector with the EPS power connector becoming an optional extra for use in high-power systems.

We wouldn't worry too much about this creating problems with support for legacy USB devices or hard drives, though. The report indicates that 3.5-inch and 2.5-inch SATA devices will be able to draw power from the motherboards instead of the PSUs.

Additionally, chances are that motherboard vendors will continue to include step-down conversion to 5V on their motherboards for legacy USB devices as long as the demand is there for it, so it could possibly take up to a decade for a full transition.

  • alextheblue
    Initially, the transition will only hit system integrators, so the DIY space will likely continue using the existing 12V ATX design for quite some time.

    The idea behind ATX12VO is that it ditches the 3.3V and 5V rails, leaving the power supply's only job as to provide 12V to the system's components. This simplifies the power circuitry design and, thus, lowers the production cost of components.
    OEMs have been doing this for years... at least HP has. In the short term I don't think it actually saved them any money, as the mainboard supplied the other voltages, so the circuitry was just moved to the motherboard. In the longer term, yeah it should save them a little bit, as they eradicate any need for legacy voltages/devices.

    I guess eventually we'll get to that point in the DIY market, and when we need 5V or 3.3 we'll have to use adapters that have built-in step downs or something. But that probably will take years.

    Side note, I hope OEMs adopt the 12VO standard instead of the proprietary crap. Using standard PSUs as replacements in certain OEM boxes has been annoying for years, in many cases I've had to either use adapters, or cut and splice.
    Reply
  • drtweak
    alextheblue said:
    OEMs have been doing this for years... at least HP has. In the short term I don't think it actually saved them any money, as the mainboard supplied the other voltages, so the circuitry was just moved to the motherboard. In the longer term, yeah it should save them a little bit, as they eradicate any need for legacy voltages/devices.

    I guess eventually we'll get to that point in the DIY market, and when we need 5V or 3.3 we'll have to use adapters that have built-in step downs or something. But that probably will take years.

    Side note, I hope OEMs adopt the 12VO standard instead of the proprietary crap. Using standard PSUs as replacements in certain OEM boxes has been annoying for years, in many cases I've had to either use adapters, or cut and splice.


    Yea Dell has been doing this for about 4 years now. it makes it a pain though from a IT point of view. Lucikly i do have 1 PSU for testing, but they also are doing a different form factor now on their PSUs so I can't even use a 24 pin adapter to their 8 pin adapter that Dell uses unless i leave the PSU hanging out. For OEM's I don't see any issue with this so long as there can be 3rd part supplies of power supplies as well. On the main stream/custom side I don't want that to ever dissapear. Some of us still run multiple hard drives ( I have 12!) and i just don't see all those amps being able to go though the motherboard.
    Reply
  • AlistairAB
    yeap we don't need any of those legacy power connectors, the vast majority need more m.2 slots and that's it
    Reply
  • InvalidError
    Ditching 3.3V and 5V from the PSU only to have motherboard manufacturers having to provide their own for PCI(e), USB and whatever else gets power from the motherboard.
    Reply
  • setx
    Moreover, various USB devices are also slowly starting to adopt 12V as their input voltage to speed up charging, and chances are that there will be a day when all new USB devices are built on using 12V rather than 5V.
    Do you even understand what you are writing about? First of all, nowhere USB specification even mentions power voltages besides 5V. It's either proprietary extensions that are going to die soon or USB-PD. And with USB-PD any other voltage besides 5V are, surprise, optional addition to 5V.

    So, 'USB' device that require 12V won't work with almost all current hardware and even then will need to negotiate 12V over 5V power first.

    Based on strong backward compatibility of USB, 5V is definitely going to stay for decades there.
    Reply
  • InvalidError
    setx said:
    So, 'USB' device that require 12V won't work with almost all current hardware and even then will need to negotiate 12V over 5V power first.
    External interfaces will have to go optical at some point due to how difficult it becomes to maintain signal integrity through multiple connectors and cables of non-trivial length. I wouldn't be surprised if USB5 introduced an optical connector spec with 12V default voltage.
    Reply
  • d0x360
    AlistairAB said:
    yeap we don't need any of those legacy power connectors, the vast majority need more m.2 slots and that's it

    Im going to disagree on that one. I have multiple SSD's in my system, Windows is on its own, then all my games are on others BUT I still have 2 HDD's for things like my download folder, my documents folder and general storage of basically anything that isn't a game.

    Also we don't need more m.2 slots we need SSD's that are larger and cheaper. If happily replace all my current SSD's with a single large drive but the price is still prohibitive.

    Lastly there is the reliability question. You can either have that power coming from a PSU that's easily switched out should it die or have all that power running through the motherboard and potentially frying it should some fault occur. It's unlikely to happen but more likely than a PSU doing the same.
    Reply
  • alextheblue
    drtweak said:
    On the main stream/custom side I don't want that to ever dissapear. Some of us still run multiple hard drives ( I have 12!) and i just don't see all those amps being able to go though the motherboard.
    For DIY though even with a 12VO PSU, you'll still have extra connectors that do NOT run through the mainboard. They'll just be 12V only. So there's no need to worry... if you have hardware that runs at 5V, for example, you could use external step-downs. It could be a board that has multiple connectors, or inline "line lump" adapters.

    Either way that is YEARS down the road, and by then all the HDDs (if you still use them at that point) will be built for 12V and handle everything on their own circuit board. So these adapters would only be used for legacy components.
    Reply
  • bit_user
    InvalidError said:
    External interfaces will have to go optical at some point
    Perhaps, but not for like keyboards, mice, sound devices, or a plethora of other USB-based peripherals and devices.

    @setx is right - USB @ 5V is going to be around for decades.
    Reply
  • daglesj
    AlistairAB said:
    yeap we don't need any of those legacy power connectors, the vast majority need more m.2 slots and that's it


    That and another 40+ PCI-e lanes on the CPU or motherboard.
    Reply