6 ms·

12VO power standard appears to be gaining steam, will reduce PC cabling, costs

77 points by CharlesW 3y ago

RedShift1 3y ago
This seems dumb to me, it just moves parts of the power supply to the motherboard. Now if there's a power problem you have to replace the entire motherboard instead of just the power supply. In a couple of years you'll have an old motherboard with no new replacement options, if it fails you basically need a new computer because newer motherboards aren't compatible with your current CPU/RAM...
- teraflop 3y ago
  Most of the motherboard's power consumption is dedicated to supplying the CPU, and that already relies on the motherboard to step down from 12V to ~1V at a very high current. The demands on the 3.3V and 5V rails are pretty small in comparison. This change is unlikely to make motherboards significantly more failure-prone than they are now.
- zx8080 3y ago
  > ...it just moves parts of the power supply to the motherboard. Intel produces motherboards, especially server-side, and has significant amount of profit from it, much less margin they get from PSUs. So it just increases profit for Intel. Consumers will likely to pay more for nothing.
- Saris 3y ago
  To be fair the CPU voltage regulators are already there, all this would require is adding a small 5V and 3.3V stage on as well. Since most of the power goes to the CPU.
elric 3y ago
> Components like RAMs, USB, and M.2 SSDs don't use 12v <snip> but 3.3V or 5V. The motherboard will be responsible for managing voltages for these components. Surely this will simply move part of the complexity from the PSU to the motherboard? Resulting in more efficient and simple PSUs, but more inefficient and complex motherboards? I've only ever had motherboards fail because of leaky capacitors or busted voltage regulators. The only PSU failure I've ever had was on account of a broken fan. Won't this lead to more motherboard failures? The cynic in me thinks that Intel would be fine with that, because that way they can sell more motherboard components.
- photonbeam 3y ago
  Half the mainboard is already just a PSU, this just means the big initial step down from 240v/120v is in a separate shielded/grounded box I somewhat wished they’d gone to 48vdc instead of 12vdc, though to further reduce cabling, but I guess that would be a big change, the 12vo seems much simpler
  - eksu 3y ago
    this is a computer not a car, 48v seems overkill and dangerous. components use 12v, 5v, or 3.3v in pcs currently. why do the step down from 48->12 instead of running 12v naturally? 12v is also what is used by the most power hungry components of a PC (GPU).
    - dist-epoch 3y ago
      The most power hungry component, the CPU, uses 1-1.5v. The GPU voltage is also step down to 1-1.5v by graphics cards VRMs.
      - connicpu 3y ago
        Power regulators that can efficiently produce the 1-1.5v output with the most minimal noise generally have lower maximums on their input voltage as well. In designing some of my own IoT devices I've looked into a fair number of power regulator ICs and 36V is a common maximum input voltage. The efficiency curves on the datasheets also usually show the efficiency gets lower the higher the input DC voltage. In a power regulator, inefficiency means even more heat you have to dissipate, not great in a GPU. I'm sure the GPU would love to take even lower voltage if it could, but 12V is the compromise we've decided on to get decent efficiency without requiring insanely thick conductors.
    - deleted 3y ago
      [deleted]
    - photonbeam 3y ago
      usbc can do 48v, its not that dangerous
Arrath 3y ago
With the rapid uptick in power draw by CPUs and GPUs perhaps its time for ATX to go and an entirely new standard to come in[0], ditching the antiquated 12v rail and step up to 24 or 48v. We've got the twin kludges of the ever growing main power plug to the motherboard and the growth of supplemental power to the GPU first a 6-pin then 8, then two 6's etc etc and now with 12vhpwr and its attendant teething pains. When is enough enough? [0]Yes, cue the xkcd comic.
- Osiris 3y ago
  Businesses seem to prefer incremental changes over large ones. Look at IPv4 vs IPv4. The two are completely incompatible and decades later we still haven’t changed. 12v is a good compromise because PSUs can be manufactured to support both the new and old standard and motherboards could even accept ATX power inputs and just ignore the 5v and 3v rails. It allows for a transition period that’s much smoother than a complete revamp. It’s the more pragmatic solution.
  - Dalewyn 3y ago
    >Look at IPv4 vs IPv4. I'm not sure if this was a typo or deliberate, but either way the irony is beautiful. >12v is a good compromise because PSUs can be manufactured to support both the new and old standard and motherboards could even accept ATX power inputs and just ignore the 5v and 3v rails. The biggest sticking point with 12VO is that it's physically incompatible with ATX. 12VO doesn't provide the voltages ATX expects (obviously), nor does 12VO provide compatible physical connections (this incompatibility is a selling point). ATX's biggest selling point and why we still use it to this day is its backwards and forwards compatibility. Outside of certain outliers you can just expect an ATX PSU to work with ATX equipment, regardless of when you buy or bought the parts; the virtues of a well-followed industry standard.
    - intrasight 3y ago
      Standards must evolve
  - aftbit 3y ago
kloch 3y ago
What is old is new again: https://en.wikipedia.org/wiki/S-100_bus https://en.wikipedia.org/wiki/S-100_bus > Power supplied on the bus is bulk unregulated +8 Volt DC and ±16 Volt DC, designed to be regulated on the cards to +5 V (used by TTL ICs), -5 V and +12 V for Intel 8080 CPU IC, ±12 V RS-232 line driver ICs, +12 V for disk drive motors. The onboard voltage regulation is typically performed by devices of the 78xx family (for example, a 7805 device to produce +5 volts). These were linear regulators which are commonly mounted on heat sinks.
- Dylan16807 3y ago
  Both kinds of power supply have existed simultaneously and in wide use for a long time. Neither design is "old". We're not going "back".
nimish 3y ago
48V now! It's already there in the server space and automotive space. Would drastically reduce cabling size and complexity. Efficiency jumps a little too. 48V to PoL is pretty common now as well.
- sowbug 3y ago
  As I understand it, 48V makes sense for the long cable runs of PoE and server racks, as well as the varying voltage needs of cars. But a PC doesn't have such runs, and 12V is already higher than any PC component's voltage. It seems like a good tradeoff.
  - samtho 3y ago
    This is correct. I see a future where there is an optional 48VDC line that is run in our homes to power stuff like LED lights and dedicated USB ports. This can become especially important for homes that use solar and stored electricity where you might be having to go from 48VDC -> 120/240VAC -> 12VDC -> 5VDC (see note) with each conversion resulting in the loss of some power due to the fact that these cannot be 100% efficient. Note: a lot of flyback-style transformers are setup to step down the AC voltage 1/10th (12V in 120VAC, 24V in 240VAC) because transformers are cheap/abundant for that. It’s cheaper often to put a buck converter that takes any voltage from 12-24V and convert it to a fixed required voltage.
    - newZWhoDis 3y ago
      If we’re moving to a new standard I’d much rather we standardize around 240V DC with an improved plug design. You’d have HUGE savings on the copper required for a standard home, plus you’d get a substantial increase in power capacity.
      - xxs 3y ago
        240VDC conversion to any low voltage (1V for cpu/gpu) won't happen. Most of the copper is spent on carrying hundreds of amps at low voltage not the 12V lanes.
hex4def6 3y ago
If you're designing a new power delivery method from scratch, I wonder if 12V is the right voltage. It seems you could take a page out of the laptop handbook and go to USB-C 20V standard. There must already be a whole ecosystem of 20V capable PMICs / SMPS already, so this doesn't seem like it would be a drastic change. Heck, it seems like we should just jump to the USB C power delivery standard for desktop PCs. The high end is currently 48V / 240W (which I'm guessing is a limitation of the connector + max safe voltage). Either go with a different design for the connector to get above 240W, or just parallel up 2-4x USB C connectors internally. That would be more than sufficient. I'm sure you'd be taking advantage of some of the production scale of laptops. And this would allow easy extension to stuff like power external monitors etc from the desktop PC directly. Being able to charge a laptop and have an external display (or two) all connected to the desktop PC instead of their own dedicated power bricks would be awesome.
geocrasher 3y ago
This is a far cry from the AT days when you could swap the motherboard power connectors and let all the magic smoke out. Those were the days. I never did it myself, but I watched a guy who was doing a working interview for a job (to be fair I was doing the same!) smoke a computer that way during his interview. They hired him anyway, and they also hired me. It ended up being the worst job I'd had to date. I don't miss the crappy computer shops of the late 90's. The good ones though, those were gold.
spuz 3y ago
I'd love to see some 12VO mini-itx boards and SFX or flex PSUs. The most challenging thing when it comes to building a small form factor PC is routing the ATX power cable and that connector is so stiff god forbid you ever need to disconnect it to do some maintenance. Small form factor PCs have benefited a lot since the move away from IDE drives but things could still be significantly improved to get more power into a small space.
- crote 3y ago
  Ironically this might actually be worse for mini-itx. In the article's images, everything to the right of the RAM slots is essentially voltage converters. Chop off everything below the PCIe slot to get a mini-itx board, and it's still 30% bigger than we're seeing today. It might allow for a slightly smaller PSU, but you get a substantially larger motherboard back in return as it needs to include voltage conversion for all the peripherals you could potentially attach. If you're making a truly tiny build you won't have much peripherals anyways so all those parts are wasted and something like a Pico PSU might already be a better option today.
pants2 3y ago
It pains me that in my home server setup, I have solar panels that produce DC, then an inverter converts that to AC for the wall outlet, then my UPS converts that to DC to charge its battery, which converts it back to AC to plug my servers into, then the server PSU converts it to DC to power the components. All that switching has to waste a lot of energy (DC->AC->DC->AC->DC).
- kayson 3y ago
  Supposing each conversion is 90% efficient, you're looking at 65.6% overall. If your server is around 300W, running 24/7 (which is what mine was before my power-reduction project), you're looking at 17kWh of waste/wk. That's quite a lot. Even if you go up to 95% it's still 13kWh...
  - fy20 3y ago
    90% is rather low today. BYD has a battery system that has a round-trip effiency of 96%. Solar inverters often have >99% effiency - although it varies across their operating range, dropping at the low end as they are optimized for peak power. https://bydbatterybox.com/uploads/downloads/230530_BYD_Battery-Box_Premium_HVS&HVM_Datasheet_V1.7_EN-647eedf90f9c3.pdf https://bydbatterybox.com/uploads/downloads/230530_BYD_Batte...
londons_explore 3y ago
They missed a trick not making this 48volt... 48 volt makes power conductors thinner and cheaper for the same functionality.
RecycledEle 3y ago
Good data on the pinouts here: https://edc.intel.com/content/www/us/en/design/products-and-solutions/processors-and-chipsets/alder-lake-s/atx12vo-12v-only-desktop-power-supply-design-guide/2.0/dc-connectors/ https://edc.intel.com/content/www/us/en/design/products-and-... I love the idea of making as many components as possible 12V-only. I think pulling the +5V from the AT-style drive connector and deleting all SATA power connectors is a mistake.

77 points by CharlesW 3y ago

This seems dumb to me, it just moves parts of the power supply to the motherboard. Now if there's a power problem you have to replace the entire motherboard instead of just the power supply. In a couple of years you'll have an old motherboard with no new replacement options, if it fails you basically need a new computer because newer motherboards aren't compatible with your current CPU/RAM...

teraflop 3y ago
Most of the motherboard's power consumption is dedicated to supplying the CPU, and that already relies on the motherboard to step down from 12V to ~1V at a very high current. The demands on the 3.3V and 5V rails are pretty small in comparison. This change is unlikely to make motherboards significantly more failure-prone than they are now.
zx8080 3y ago
> ...it just moves parts of the power supply to the motherboard. Intel produces motherboards, especially server-side, and has significant amount of profit from it, much less margin they get from PSUs. So it just increases profit for Intel. Consumers will likely to pay more for nothing.
Saris 3y ago
To be fair the CPU voltage regulators are already there, all this would require is adding a small 5V and 3.3V stage on as well. Since most of the power goes to the CPU.

elric 3y ago

> Components like RAMs, USB, and M.2 SSDs don't use 12v <snip> but 3.3V or 5V. The motherboard will be responsible for managing voltages for these components. Surely this will simply move part of the complexity from the PSU to the motherboard? Resulting in more efficient and simple PSUs, but more inefficient and complex motherboards? I've only ever had motherboards fail because of leaky capacitors or busted voltage regulators. The only PSU failure I've ever had was on account of a broken fan. Won't this lead to more motherboard failures? The cynic in me thinks that Intel would be fine with that, because that way they can sell more motherboard components.

photonbeam 3y ago
Half the mainboard is already just a PSU, this just means the big initial step down from 240v/120v is in a separate shielded/grounded box I somewhat wished they’d gone to 48vdc instead of 12vdc, though to further reduce cabling, but I guess that would be a big change, the 12vo seems much simpler
- eksu 3y ago
  this is a computer not a car, 48v seems overkill and dangerous. components use 12v, 5v, or 3.3v in pcs currently. why do the step down from 48->12 instead of running 12v naturally? 12v is also what is used by the most power hungry components of a PC (GPU).
  - dist-epoch 3y ago
    The most power hungry component, the CPU, uses 1-1.5v. The GPU voltage is also step down to 1-1.5v by graphics cards VRMs.
    - connicpu 3y ago
      Power regulators that can efficiently produce the 1-1.5v output with the most minimal noise generally have lower maximums on their input voltage as well. In designing some of my own IoT devices I've looked into a fair number of power regulator ICs and 36V is a common maximum input voltage. The efficiency curves on the datasheets also usually show the efficiency gets lower the higher the input DC voltage. In a power regulator, inefficiency means even more heat you have to dissipate, not great in a GPU. I'm sure the GPU would love to take even lower voltage if it could, but 12V is the compromise we've decided on to get decent efficiency without requiring insanely thick conductors.
  - deleted 3y ago
    [deleted]
  - photonbeam 3y ago
    usbc can do 48v, its not that dangerous

Arrath 3y ago

With the rapid uptick in power draw by CPUs and GPUs perhaps its time for ATX to go and an entirely new standard to come in[0], ditching the antiquated 12v rail and step up to 24 or 48v. We've got the twin kludges of the ever growing main power plug to the motherboard and the growth of supplemental power to the GPU first a 6-pin then 8, then two 6's etc etc and now with 12vhpwr and its attendant teething pains. When is enough enough? [0]Yes, cue the xkcd comic.

Osiris 3y ago
Businesses seem to prefer incremental changes over large ones. Look at IPv4 vs IPv4. The two are completely incompatible and decades later we still haven’t changed. 12v is a good compromise because PSUs can be manufactured to support both the new and old standard and motherboards could even accept ATX power inputs and just ignore the 5v and 3v rails. It allows for a transition period that’s much smoother than a complete revamp. It’s the more pragmatic solution.
- Dalewyn 3y ago
  >Look at IPv4 vs IPv4. I'm not sure if this was a typo or deliberate, but either way the irony is beautiful. >12v is a good compromise because PSUs can be manufactured to support both the new and old standard and motherboards could even accept ATX power inputs and just ignore the 5v and 3v rails. The biggest sticking point with 12VO is that it's physically incompatible with ATX. 12VO doesn't provide the voltages ATX expects (obviously), nor does 12VO provide compatible physical connections (this incompatibility is a selling point). ATX's biggest selling point and why we still use it to this day is its backwards and forwards compatibility. Outside of certain outliers you can just expect an ATX PSU to work with ATX equipment, regardless of when you buy or bought the parts; the virtues of a well-followed industry standard.
  - intrasight 3y ago
    Standards must evolve
- aftbit 3y ago

kloch 3y ago

What is old is new again: https://en.wikipedia.org/wiki/S-100_bus https://en.wikipedia.org/wiki/S-100_bus > Power supplied on the bus is bulk unregulated +8 Volt DC and ±16 Volt DC, designed to be regulated on the cards to +5 V (used by TTL ICs), -5 V and +12 V for Intel 8080 CPU IC, ±12 V RS-232 line driver ICs, +12 V for disk drive motors. The onboard voltage regulation is typically performed by devices of the 78xx family (for example, a 7805 device to produce +5 volts). These were linear regulators which are commonly mounted on heat sinks.

Dylan16807 3y ago
Both kinds of power supply have existed simultaneously and in wide use for a long time. Neither design is "old". We're not going "back".

nimish 3y ago

48V now! It's already there in the server space and automotive space. Would drastically reduce cabling size and complexity. Efficiency jumps a little too. 48V to PoL is pretty common now as well.

sowbug 3y ago
As I understand it, 48V makes sense for the long cable runs of PoE and server racks, as well as the varying voltage needs of cars. But a PC doesn't have such runs, and 12V is already higher than any PC component's voltage. It seems like a good tradeoff.
- samtho 3y ago
  This is correct. I see a future where there is an optional 48VDC line that is run in our homes to power stuff like LED lights and dedicated USB ports. This can become especially important for homes that use solar and stored electricity where you might be having to go from 48VDC -> 120/240VAC -> 12VDC -> 5VDC (see note) with each conversion resulting in the loss of some power due to the fact that these cannot be 100% efficient. Note: a lot of flyback-style transformers are setup to step down the AC voltage 1/10th (12V in 120VAC, 24V in 240VAC) because transformers are cheap/abundant for that. It’s cheaper often to put a buck converter that takes any voltage from 12-24V and convert it to a fixed required voltage.
  - newZWhoDis 3y ago
    If we’re moving to a new standard I’d much rather we standardize around 240V DC with an improved plug design. You’d have HUGE savings on the copper required for a standard home, plus you’d get a substantial increase in power capacity.
    - xxs 3y ago
      240VDC conversion to any low voltage (1V for cpu/gpu) won't happen. Most of the copper is spent on carrying hundreds of amps at low voltage not the 12V lanes.

hex4def6 3y ago

If you're designing a new power delivery method from scratch, I wonder if 12V is the right voltage. It seems you could take a page out of the laptop handbook and go to USB-C 20V standard. There must already be a whole ecosystem of 20V capable PMICs / SMPS already, so this doesn't seem like it would be a drastic change. Heck, it seems like we should just jump to the USB C power delivery standard for desktop PCs. The high end is currently 48V / 240W (which I'm guessing is a limitation of the connector + max safe voltage). Either go with a different design for the connector to get above 240W, or just parallel up 2-4x USB C connectors internally. That would be more than sufficient. I'm sure you'd be taking advantage of some of the production scale of laptops. And this would allow easy extension to stuff like power external monitors etc from the desktop PC directly. Being able to charge a laptop and have an external display (or two) all connected to the desktop PC instead of their own dedicated power bricks would be awesome.

geocrasher 3y ago

This is a far cry from the AT days when you could swap the motherboard power connectors and let all the magic smoke out. Those were the days. I never did it myself, but I watched a guy who was doing a working interview for a job (to be fair I was doing the same!) smoke a computer that way during his interview. They hired him anyway, and they also hired me. It ended up being the worst job I'd had to date. I don't miss the crappy computer shops of the late 90's. The good ones though, those were gold.

spuz 3y ago

I'd love to see some 12VO mini-itx boards and SFX or flex PSUs. The most challenging thing when it comes to building a small form factor PC is routing the ATX power cable and that connector is so stiff god forbid you ever need to disconnect it to do some maintenance. Small form factor PCs have benefited a lot since the move away from IDE drives but things could still be significantly improved to get more power into a small space.

crote 3y ago
Ironically this might actually be worse for mini-itx. In the article's images, everything to the right of the RAM slots is essentially voltage converters. Chop off everything below the PCIe slot to get a mini-itx board, and it's still 30% bigger than we're seeing today. It might allow for a slightly smaller PSU, but you get a substantially larger motherboard back in return as it needs to include voltage conversion for all the peripherals you could potentially attach. If you're making a truly tiny build you won't have much peripherals anyways so all those parts are wasted and something like a Pico PSU might already be a better option today.

pants2 3y ago

It pains me that in my home server setup, I have solar panels that produce DC, then an inverter converts that to AC for the wall outlet, then my UPS converts that to DC to charge its battery, which converts it back to AC to plug my servers into, then the server PSU converts it to DC to power the components. All that switching has to waste a lot of energy (DC->AC->DC->AC->DC).

kayson 3y ago
Supposing each conversion is 90% efficient, you're looking at 65.6% overall. If your server is around 300W, running 24/7 (which is what mine was before my power-reduction project), you're looking at 17kWh of waste/wk. That's quite a lot. Even if you go up to 95% it's still 13kWh...
- fy20 3y ago
  90% is rather low today. BYD has a battery system that has a round-trip effiency of 96%. Solar inverters often have >99% effiency - although it varies across their operating range, dropping at the low end as they are optimized for peak power. https://bydbatterybox.com/uploads/downloads/230530_BYD_Battery-Box_Premium_HVS&HVM_Datasheet_V1.7_EN-647eedf90f9c3.pdf https://bydbatterybox.com/uploads/downloads/230530_BYD_Batte...

londons_explore 3y ago

They missed a trick not making this 48volt... 48 volt makes power conductors thinner and cheaper for the same functionality.

RecycledEle 3y ago

Good data on the pinouts here: https://edc.intel.com/content/www/us/en/design/products-and-solutions/processors-and-chipsets/alder-lake-s/atx12vo-12v-only-desktop-power-supply-design-guide/2.0/dc-connectors/ https://edc.intel.com/content/www/us/en/design/products-and-... I love the idea of making as many components as possible 12V-only. I think pulling the +5V from the AT-style drive connector and deleting all SATA power connectors is a mistake.