7 ms·

I'm curious as to why no vendor has yet tried to push a 24V or 48V PSU rail standard to reduce the amperage pushed over these crappy pins. Of course then the bo

by bri3d 4y ago

I'm curious as to why no vendor has yet tried to push a 24V or 48V PSU rail standard to reduce the amperage pushed over these crappy pins. Of course then the board itself needs to be able to handle the higher voltage for down-conversion, but don't these systems usually use switching / Buck regulators as the first stage anyway, which could easily be tuned to handle the higher input voltage with minimal loss added?

LarsAlereon 4y ago
The Power Stamp Alliance was working on 48v modular VRMs for HPC and servers, but I haven't seen any news in the past couple of years.
allenrb 4y ago
Yes, exactly. Even before this issue, ATX 3.0 felt like a missed opportunity to start phasing in 48v DC power. Very disappointing.
scalablenotions 4y ago
As someone who tinkers with these things a lot, I'm happy for the voltage I'm playing with not to be increased. There's plenty of scope to improve the plug design without approaching anything near the fragility of this nVidia adapter. There's no pressing need to increase voltage.
- pathartl 4y ago
  The fragility I think is the main concern here, like you said. I hate when I have three 12v, 8 pin connectors on my GPU. I would be ecstatic between that and a small connector that catches fire if it's not perfectly 100% seated and strain relieved.
- mmoskal 4y ago
  I believe 48V would be used since 50V is the maximum voltage considered "safe" for humans. This is also why USB-C goes up to 48V.
  - sidewndr46 4y ago
    It works the other way too. Low voltage is not really "safe", we can just tolerate the risk most of the time. Soak your hands in some saltwater & then grab 12 volt rails, it'll hurt like hell.
    - flatiron 4y ago
      “Lick a 9V” is usually how I phrase it. Not the best feeling in the world.
GekkePrutser 4y ago
I have a feeling this will make the DC-DC converters more bulky and hot on the card itself. Not entirely sure though as I've never built those. However in the longer term it's probably time to start optimizing for power efficiency just like Intel did after the pentium 4. Cards can't keep increasing requirements in this day of energy crisis. And the climate problem insures it'll be like that for a long time.
- postalrat 4y ago
  Is a 12v to whatever voltages the chips on the card use smaller than a 48v to whatever voltages the chips use?
  - eyegor 4y ago
    Generally the final stage is in the 1v ballpark. Giant buck converters are already the standard and we're still below 1kW for the foreseeable future so you don't even need something novel. Examples: https://www.powerelectronictips.com/powering-graphics-processors-from-a-48-v-bus/ https://www.powerelectronictips.com/powering-graphics-proces...
paulmd 4y ago
> I'm curious as to why no vendor has yet tried to push a 24V or 48V PSU rail standard to reduce the amperage pushed over these crappy pins. people on another HN thread yesterday literally were bitching about the cost (not safety - cost) of a $1 adapter being "forced" on them by NVIDIA and now you want to tell them they're gonna have to buy a whole new PSU? that's gonna be quite the comment thread. but yeah you're right in general, gotta move to 48V to move forward, pushing infinite amps at low voltages is completely bass-ackwards. The pcie-add-in-card form-factor needs a rethink in general, the GPU is now the largest and most power-hungry part of the system by far, and power isn't the only problem imposed by that ancient AT standard. imo we should move to some standardized "module sizes" for GPUs so that we solve GPU sag and cooling at the same time. the "pcie card" of the future should be a 12x6x4" prismatic module that slides on rails into a socket that provides a PCIe edge connector as well as a XT90 jag (or similar) for power, at a defined physical location, with 48V. Airflow should happen in a defined direction and manner, whether that's axial flow or blower-style. also please for the love of god, hot air rises, the AT standard means axial coolers are pushing against convection. But we couldn't even get BTX to take off, which is a trivial modification of ATX to reverse the orientation and fix this problem, the DIY market is deeply deeply rooted in the 1980s and will not abandon ATX without some nudging. Enterprise and OEM are fine, their volumes are big enough to do their own thing, but consumers are spinning their wheels fighting IBM's 1980 mistakes. It's gonna take government intervention, the EU is gonna have to step in and do it like with USB-C cables. The mess of arbitrary card dimensions slowly growing larger over time is the exact same problem that we had pre-standardization with USB too.
- codeflo 4y ago
  I think at these sizes and weights, the GPU needs to become a board that you screw onto the case, like a second motherboard. Sagging solved. Now the noisy fan, replace it with a preinstalled water cooling block to be integrated with your overall cooling solution, voila: noise and weird airflow solved as well.
  - paulmd 4y ago
    Exactly, that's what I mean by "on rails". Imagine sliding a server PSU into place and it latches as it seats... do that but with a "GPU module". The case itself needs to be part of the support to fix GPU sag, and that's only possible with dimensional and connectical standardization. Smaller stuff that still reflects the "add-in-card" intention of the original design is fine, you can still have a bunch of PCIe slots for network cards and USB controllers if you want. But the GPU is not really an "add-in-card" anymore and it's problematic in a design sense to keep acting like it is, let alone to have every single product on the market doing something completely different dimensionally. That's the "pre-USB-micro" era problem that USB faced. There's no need for water though, that's a whole can of worms.
ryzvonusef 4y ago
Because we are still in the era of trying to move from 3V/5V to 12V! Power Supply Manufacturers and Board Manufactures can't still agree on this little step. 24V/48V is a bridge too far! Same issue has been plaguing the automobile industry, they can't wait to move from 12V to 48V for their low voltage works, but who will bell the cat?
- vhab 4y ago
  Interestingly though, there's a slow but steady push towards 24V on boats. More electronics are available in 24V version or simply support both 12V and 24V. And new boats tend to have a 12V and 24V bank. Electric sailboats usually have a 48V bank as well. And in an entirely different area, 3D printing completed their transition from 12V to 24V some years ago, and currently there's an active push towards 48V. I'm personally just looking forward to not spend a fortune on cables due to low voltages. It's frustratingly expensive to carry 12V a decent distance with some higher current draws.
- jandrese 4y ago
  > they can't wait to move from 12V to 48V for their low voltage works That would be a surprising move to be sure. I assume you mean low wattage?
  - ryzvonusef 4y ago
    Sorry, Yes.
  - AdrianB1 4y ago
    In electric vehicles is also low voltage. In ICE, it is all (mains) voltage and wattage, including the battery.
- bsder 4y ago
  Actually, I thought the issue with automotive is that 48V really isn't enough. My understanding is that actuators want to be operating at much higher voltages and that 100V-ish is the lowest they really want and that modern actuators would much prefer to be up at 200-400V.
amelius 4y ago
Instead of introducing a new PSU standard, why not change the connector, or add a connector for power.
- masklinn 4y ago
  Because you still have the issue that you need to push insane amperages if you’re limited to 12V. 600W out of 12V require 50 amps. This means you need more connectors, thicker cables and you have more resistive losses (= heat). If you can get 48 V rails in, then you get down to a much comfier 12.5A, you can get that through comfortably on a pair of small-section wires.
zbrozek 4y ago
I sort of wish that we used something more like this[0] for add-on module power connectors. And a better mechanical design. The perpendicular card form-factor is silly. [0] https://www.farnell.com/datasheets/1716278.pdf https://www.farnell.com/datasheets/1716278.pdf
TD-Linux 4y ago
The loss of a higher buck ratio is not insignificant. It requires higher voltage rated mosfets which generally have worse performance, as well as increased switching losses resulting in more heat where you least want it. Most other use cases for 24/48V involve significantly longer wires than in a PC case. I think the actual net win, if any, would be quite small.
fennecfoxy 4y ago
I just want the 24pin to go away already. It's so wide/molex really sucks hard for small cases.

by bri3d 4y ago

LarsAlereon 4y ago

The Power Stamp Alliance was working on 48v modular VRMs for HPC and servers, but I haven't seen any news in the past couple of years.

allenrb 4y ago

Yes, exactly. Even before this issue, ATX 3.0 felt like a missed opportunity to start phasing in 48v DC power. Very disappointing.

scalablenotions 4y ago

As someone who tinkers with these things a lot, I'm happy for the voltage I'm playing with not to be increased. There's plenty of scope to improve the plug design without approaching anything near the fragility of this nVidia adapter. There's no pressing need to increase voltage.

pathartl 4y ago
The fragility I think is the main concern here, like you said. I hate when I have three 12v, 8 pin connectors on my GPU. I would be ecstatic between that and a small connector that catches fire if it's not perfectly 100% seated and strain relieved.
mmoskal 4y ago
I believe 48V would be used since 50V is the maximum voltage considered "safe" for humans. This is also why USB-C goes up to 48V.
- sidewndr46 4y ago
  It works the other way too. Low voltage is not really "safe", we can just tolerate the risk most of the time. Soak your hands in some saltwater & then grab 12 volt rails, it'll hurt like hell.
  - flatiron 4y ago
    “Lick a 9V” is usually how I phrase it. Not the best feeling in the world.

GekkePrutser 4y ago

I have a feeling this will make the DC-DC converters more bulky and hot on the card itself. Not entirely sure though as I've never built those. However in the longer term it's probably time to start optimizing for power efficiency just like Intel did after the pentium 4. Cards can't keep increasing requirements in this day of energy crisis. And the climate problem insures it'll be like that for a long time.

postalrat 4y ago
Is a 12v to whatever voltages the chips on the card use smaller than a 48v to whatever voltages the chips use?
- eyegor 4y ago
  Generally the final stage is in the 1v ballpark. Giant buck converters are already the standard and we're still below 1kW for the foreseeable future so you don't even need something novel. Examples: https://www.powerelectronictips.com/powering-graphics-processors-from-a-48-v-bus/ https://www.powerelectronictips.com/powering-graphics-proces...

paulmd 4y ago

> I'm curious as to why no vendor has yet tried to push a 24V or 48V PSU rail standard to reduce the amperage pushed over these crappy pins. people on another HN thread yesterday literally were bitching about the cost (not safety - cost) of a $1 adapter being "forced" on them by NVIDIA and now you want to tell them they're gonna have to buy a whole new PSU? that's gonna be quite the comment thread. but yeah you're right in general, gotta move to 48V to move forward, pushing infinite amps at low voltages is completely bass-ackwards. The pcie-add-in-card form-factor needs a rethink in general, the GPU is now the largest and most power-hungry part of the system by far, and power isn't the only problem imposed by that ancient AT standard. imo we should move to some standardized "module sizes" for GPUs so that we solve GPU sag and cooling at the same time. the "pcie card" of the future should be a 12x6x4" prismatic module that slides on rails into a socket that provides a PCIe edge connector as well as a XT90 jag (or similar) for power, at a defined physical location, with 48V. Airflow should happen in a defined direction and manner, whether that's axial flow or blower-style. also please for the love of god, hot air rises, the AT standard means axial coolers are pushing against convection. But we couldn't even get BTX to take off, which is a trivial modification of ATX to reverse the orientation and fix this problem, the DIY market is deeply deeply rooted in the 1980s and will not abandon ATX without some nudging. Enterprise and OEM are fine, their volumes are big enough to do their own thing, but consumers are spinning their wheels fighting IBM's 1980 mistakes. It's gonna take government intervention, the EU is gonna have to step in and do it like with USB-C cables. The mess of arbitrary card dimensions slowly growing larger over time is the exact same problem that we had pre-standardization with USB too.

codeflo 4y ago
I think at these sizes and weights, the GPU needs to become a board that you screw onto the case, like a second motherboard. Sagging solved. Now the noisy fan, replace it with a preinstalled water cooling block to be integrated with your overall cooling solution, voila: noise and weird airflow solved as well.
- paulmd 4y ago
  Exactly, that's what I mean by "on rails". Imagine sliding a server PSU into place and it latches as it seats... do that but with a "GPU module". The case itself needs to be part of the support to fix GPU sag, and that's only possible with dimensional and connectical standardization. Smaller stuff that still reflects the "add-in-card" intention of the original design is fine, you can still have a bunch of PCIe slots for network cards and USB controllers if you want. But the GPU is not really an "add-in-card" anymore and it's problematic in a design sense to keep acting like it is, let alone to have every single product on the market doing something completely different dimensionally. That's the "pre-USB-micro" era problem that USB faced. There's no need for water though, that's a whole can of worms.

ryzvonusef 4y ago

Because we are still in the era of trying to move from 3V/5V to 12V! Power Supply Manufacturers and Board Manufactures can't still agree on this little step. 24V/48V is a bridge too far! Same issue has been plaguing the automobile industry, they can't wait to move from 12V to 48V for their low voltage works, but who will bell the cat?

vhab 4y ago
Interestingly though, there's a slow but steady push towards 24V on boats. More electronics are available in 24V version or simply support both 12V and 24V. And new boats tend to have a 12V and 24V bank. Electric sailboats usually have a 48V bank as well. And in an entirely different area, 3D printing completed their transition from 12V to 24V some years ago, and currently there's an active push towards 48V. I'm personally just looking forward to not spend a fortune on cables due to low voltages. It's frustratingly expensive to carry 12V a decent distance with some higher current draws.
jandrese 4y ago
> they can't wait to move from 12V to 48V for their low voltage works That would be a surprising move to be sure. I assume you mean low wattage?
- ryzvonusef 4y ago
  Sorry, Yes.
- AdrianB1 4y ago
  In electric vehicles is also low voltage. In ICE, it is all (mains) voltage and wattage, including the battery.
bsder 4y ago
Actually, I thought the issue with automotive is that 48V really isn't enough. My understanding is that actuators want to be operating at much higher voltages and that 100V-ish is the lowest they really want and that modern actuators would much prefer to be up at 200-400V.

amelius 4y ago

Instead of introducing a new PSU standard, why not change the connector, or add a connector for power.

masklinn 4y ago
Because you still have the issue that you need to push insane amperages if you’re limited to 12V. 600W out of 12V require 50 amps. This means you need more connectors, thicker cables and you have more resistive losses (= heat). If you can get 48 V rails in, then you get down to a much comfier 12.5A, you can get that through comfortably on a pair of small-section wires.

zbrozek 4y ago

I sort of wish that we used something more like this[0] for add-on module power connectors. And a better mechanical design. The perpendicular card form-factor is silly. [0] https://www.farnell.com/datasheets/1716278.pdf https://www.farnell.com/datasheets/1716278.pdf

TD-Linux 4y ago

The loss of a higher buck ratio is not insignificant. It requires higher voltage rated mosfets which generally have worse performance, as well as increased switching losses resulting in more heat where you least want it. Most other use cases for 24/48V involve significantly longer wires than in a PC case. I think the actual net win, if any, would be quite small.

fennecfoxy 4y ago

I just want the 24pin to go away already. It's so wide/molex really sucks hard for small cases.