ATX12VO - Help me here

Intel spec:

GamersNexus video:

3.3V and 5V conversion moves from the PSU and on to the motherboard.

So far for the spec and overview.
Now what confuses me as to what makes this an improvement. IMO it is a step back and off a cliff.


  • 5.25" ODD uses 12V and 5V from the SATA connector

  • 3.5" HDDs use all the voltages from SATA

  • 2.5" SSDs use 5V, some 3.3V

  • M.2 SSDs get supplied 3.3V

  • -12V is needed to get the 24V ∆V Op-Amps need (used for various sensing duties)

Instead of having all that come from one connector, it now has to be converted locally.
After looking at your mobo, you will notice the only area that could in a pinch accommodate is near the chipset. Which board vendors established when X570 appeared, needs a fan because test cuts with a chop-saw heatsinks do not work in the hot exhaust from a GPU or two…

And that area will now handle DC-DC conversion to supply your storage media?

On the note of storage:
USB is 5V and has been for ever. And it makes sense as 5V is not just a great supply voltage but also very nice for logic-level signals.
Now imagine if all your USB-drives had a hump to accomodate the DC-DC stepdown from 12V to 5V or 3.3V.
Not to talk about microSD cards for now…

So now I turn to you all:
What am I missing that makes 12V-only for home use the next big thing since sliced bread?`

It’s for system integrators not the enthusiasts

This is not getting rid of 5/3.3v, just moving it to the motherboard. So both of these are not going to happen, since the motherboard will be able to supply the correct voltage.

If you watch the entire video, this is aimed at prebuilt systems only, and probably mostly SFF machines. If you have looked at those motherboards, they have more room to place this, especially as the PSU size is shrunk so there is more room for the mobo.

New laws that require the development of new stuff to allow lower power at idle. So it is not that this is an amazing new development, it is that this is forced upon OEMs by California. And intel still wants some standardization and also to have some control of the standardization so that is why they published this instead of letting individual OEMs try to make their own solutions.

I think 12v only tiny PSUs would be great.

I could use them with easily with my pico PSUs.

Which never bleeds over to anywhere else. Apart from that, Intel mentioned “High End Desktop Market” in their specs.

To what free spot? Even OEM boards in simple systems are cramped.

We had amazingly bad VRM designs on mobos, and still have.

We are still talking ATX form factors here. Mobo, Case and PSU remain the same physically.

I have to seriously question this then.
Instead of having one PSU that lasts many upgrade cycles, users with this system will toss out all the various voltage regulators with every motherboard (and potential GPU, yes there is a 3.3V rail
in the PCIe slot) change.
Same as with lead free solder cracking prematurely, this will create more fill for the ever growing landfills.

This is for prebuilts. Who would pull a PSU out of a prebuilt and resuse for multiple upgrade cycles? It probably happens often enough, but %1 of the time is probably generous.

This is a very good point, powered USB hubs may make a major comeback. Also, running an HDD may not always work if the mobo is sucky.

Bye bye top two PCIe slots?

This spec also includes other form factor motherboards, and there is no reason the connector and pinouts and whatnot could not be put on custom form factor.

It’s fairly simple, buddy…
4 equal resistances can momentarily split that 12V input into 4x3V outputs.
2 equal resistances can split it into 2x6V outputs.
All of this can be done no problem what so ever on the board itself.
Stabilization of the voltage is just a couple transistors, and you don’t really need much since you have perfectly stable input from the PSU.
This ain’t really adding anything that problematic to any component.

I see your argument, we have standards that work, don’t fix what isn’t broken, don’t do solutions for non existing issues. I am also not entirely sure what the benefits of this is, but as far as I can see there aren’t really many negatives…

That is not how that works pete

What is not how what works?

will never be the way to hit the power the efficiency rating they are looking for… more than likely they will use buck converters.

I love how people missed my point to argue specifics… Some not even arguing, just telling me I am wrong.

The point is it’s not so difficult to lower the voltage from 12 to 5… The main issue is going from 220 or 110 to 12 and the PSU still takes care of that.

goes on to describe an LDO

Super simple stuff.

That’s actually the easy part. The hard part is switching and protection circuits.

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