6 ms·

If only we had connectors which could actually handle such currents. Maybe something along the lines of an XT90, but no Nvidia somehow wants to save a bit of sp

If only we had connectors which could actually handle such currents. Maybe something along the lines of an XT90, but no Nvidia somehow wants to save a bit of space or weight on their huge brick of a card. I don't get it.

Joker_vD 2y ago
If only we had electrical and thermal fuses that could be used to protect the connectors and wires.
michaelt 2y ago
The USB-C connectors on laptops and phones can deliver 240 watts [1] in a 8.4x2.7mm connector. 12VHPWR is 8.4x20.8mm so it's got 7.7x the cross-sectional area but transmits only 2.5x the power. And 12VHPWR also has the substantial advantage that GPUs have fans and airflow aplenty. So I can see why someone looking at the product might have thought the connector could reasonably be shrunk. Of course, the trick USB-C uses is to deliver 5A at 48v, instead of 50A at 12v [1] https://en.wikipedia.org/wiki/USB-C#Power_delivery https://en.wikipedia.org/wiki/USB-C#Power_delivery
- 6SixTy 2y ago
  Nobody thought that they could push 50A at 12V through half the connector. It's management wanting to push industrial design as opposed to safety. They made a new connector borrowing from an already existing design, pushed up the on paper amperage by 3A, never changed the contact resistance, and made the parent connector push current near it's limit (10.5A max vs 8.3A). And oh, the insertion force is so, so much higher than ever before. Previous PCIe connectors push about 4A through a connector designed for about 13A. Worth also mentioning that the same time the 12VHPWR connector was being market tested was during Ampere, the same generation where Nvidia doubled down on the industrial design of their 1st party cards. Also there's zero devices out there that actually deliver or take 240W over USB-C. Texas Instruments literally only released the datasheets for a pivotal supporting IC within the last 6 months.
  - michaelt 2y ago
    > Nobody thought that they could push 50A at 12V through half the connector. If you're saying that the connector doesn't have a 2x safety factor then I'd agree, sure. But I can see how the connector passed through the design reviews, for the 40x0 era cards. The cables are thick enough. The pins seem adequate, especially assuming any GPU that's drawing maximum power will have its fans producing lots of airflow; plenty of connectors get a little warm. There's no risk of partial insertion, because the connector is keyed, and there's a plastic latch that engages with a click, and there's four extra sense pins. I can see how that would have seemed like a belt-and-braces approach. Obviously after the first round of melted connectors they should have fixed things properly. I'm just saying to me this seems like regular negligence, rather than gross negligence.
  - crote 2y ago
    > Also there's zero devices out there that actually deliver or take 240W over USB-C. Texas Instruments literally only released the datasheets for a pivotal supporting IC within the last 6 months. The 16-inch Framework laptop can take 240W power. For chargers, the Delta Electronics ADP-240KB is an option. Some Framework users have already tried the combination.
- kersplody 2y ago
  The connector could reasonably be shrunk. It just now has essentially no design margin so any minor issue immediately becomes major! 50A DC is serious current to be treated with respect. 5A DC is sanely manageable.
- Miraste 2y ago
  The spec may say it, but I've never encountered a USB-C cable that claims to support 240 watts. I suspect if machines that tried to draw 240W over USB-C were widespread, we would see a lot of melted cables and fires. There are enough of them already with lower power draw charging.
  - DebtDeflation 2y ago
    Search Amazon for "240W USB" and you get multiple pages of results for cables. A few years ago there was a recall of OnePlus cables that were melting and catching fire, I had 2 of them and both melted. But yes 240W/48V/5A is insane for a spec that was originally designed for 0.5W/5V/100mA. I suspect this is the limit for USB charging as anything over 48V is considered a shock hazard by UL and 5A is already at the very top of the 3-5A limit of 20AWG for fire safety.
    - makeitdouble 2y ago
      We've had a variety of 140W laptops for a few years already, so the original spec has been far away for a while now. The advantage of USB-C is the power negotiation, so getting the higher rating only on circuits that actually support it should de doable and relatively safe. The OnePlus cable melting give me the same impression as when hair power cables melt: it's a solved problem, the onus is on the maker.
  - makeitdouble 2y ago
    240W cables are here but at around a 10x price premium. Also cables are chipped so e.g. a 100W cable won't allow 240 in the first place. Users needing the 240W have a whole chain of specialized devices, so buying a premium cable is also not much of an issue.
baq 2y ago
At these wattages just give it its own mains plug.
- Joker_vD 2y ago
  Also put it in a separate case, and give it an OcuLink cable to attach to the main desktop tower. I suspect that's exactly where we're heading, to be fair.
  - dylan604 2y ago
    I've built video rigs that did just that. An external expansion chassis that you could put additional PCIe cards when the host only had 3 slots. The whole eGPU used to be a cute thing, but it might have been more foreshadowing than we realized.
    - fooker 2y ago
      Have you measured latency? In modern(last 4 years approximately) GPUs, physical wiring distance is starting to contribute substantially to latency.
      - dylan604 2y ago
        There were no latency concerns. These were video rigs, not realtime shoot'em ups. They were compute devices running color correction and other filters type of thing, not pushing a video signal to a monitor 60fps 240Hz refresh nonsense. These did real work /s
        fooker 2y ago
        Ah makes sense, the other kind of graphics!
      - KeplerBoy 2y ago
        latency due to wiring distances is far from being an issue in these scenarios. The signals travel at the speed of light. 186 miles per millisecond. The problem you will encounter with pcie gen5 risers is signal integrity.
short_sells_poo 2y ago
This is the top end halo product. What's wrong with pushing the envelope? Should we all play tetris because "what's wrong with block graphics?". I'm not defending the shitty design here, but I'm all for always pushing the boundaries.
- KeplerBoy 2y ago
  Pushing the boundaries of a simple connector is not innovation, that's just reckless and a fire hazard.
deleted 2y ago
[deleted]
mschuster91 2y ago
> If only we had connectors which could actually handle such currents. The problem isn't connectors, the problem (fundamentally) is to share electric connectivity between multiple conductors. Sure, you can run 16A over 1.5 mm² wires, and 32A over 2.5 mm² (taken from [1], yes it's for 230V but that doesn't matter, the current is important not the voltage). And theoretically you could run 32A over 2x 1.5 mm² (you'd end up with 3 mm² cross section), but it's not allowed by code as when, for any reason, either of the two legs disconnects entirely or has increased resistance e.g. due to corrosion or a loose screw / wire nut (hence, please always use Wago style clamps - screws and wire nuts are not safe, even if torqued properly which most people don't), suddenly the other leg has to carry (much) more current than it's designed for and you risk anything from molten connectors to an outright fire. And that is what NVidia currently is running into, together with bad connections (e.g. due to dirt ingress). The correct solution would be for the GPU to not tie together the incoming individual 12VHPWR pins on a single plane right at the connector input but to use MOSFETs and current/voltage sense to detect stuff like different current availability (at least it used to be the case with older GPUs that there were multiple ways to supply them with power and only, say, one of two connectors on the GPU being used) or overcurrents due to something going bad. But that adds complexity and, at least for the overcurrent protection, yet another microcontroller plus one ADC for each incoming power pin. Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry. Another and even more annoying issue by the way is grounding - because all the electricity that comes in also wants to go back to the PSU and it can take any number of paths - the PCIe connector, the metal backplate, the 12VHPWR extra connector, via the shield of a DP cable that goes to a Thunderbolt adapter card's video input to that card, via the SLI connector to the other GPU and its ground... Electricity is fun! [1] https://stex24.com/de/ratgeber/strombelastbarkeit https://stex24.com/de/ratgeber/strombelastbarkeit
- Dylan16807 2y ago
  > The correct solution would be for the GPU to not tie together the incoming individual 12VHPWR pins on a single plane right at the connector input but to use MOSFETs and current/voltage sense to detect stuff like different current availability (at least it used to be the case with older GPUs that there were multiple ways to supply them with power and only, say, one of two connectors on the GPU being used) or overcurrents due to something going bad. But that adds complexity and, at least for the overcurrent protection, yet another microcontroller plus one ADC for each incoming power pin. > Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry. So as you say, monitoring multiple inputs happened on the older xx90s, and most cards still do it. It's not hard. Multiple DC-DC converters is something every GPU has. That's the only way to get enough current. So all you have to do is connect them to specific pins.

Joker_vD 2y ago

If only we had electrical and thermal fuses that could be used to protect the connectors and wires.

michaelt 2y ago

The USB-C connectors on laptops and phones can deliver 240 watts [1] in a 8.4x2.7mm connector. 12VHPWR is 8.4x20.8mm so it's got 7.7x the cross-sectional area but transmits only 2.5x the power. And 12VHPWR also has the substantial advantage that GPUs have fans and airflow aplenty. So I can see why someone looking at the product might have thought the connector could reasonably be shrunk. Of course, the trick USB-C uses is to deliver 5A at 48v, instead of 50A at 12v [1] https://en.wikipedia.org/wiki/USB-C#Power_delivery https://en.wikipedia.org/wiki/USB-C#Power_delivery

6SixTy 2y ago
Nobody thought that they could push 50A at 12V through half the connector. It's management wanting to push industrial design as opposed to safety. They made a new connector borrowing from an already existing design, pushed up the on paper amperage by 3A, never changed the contact resistance, and made the parent connector push current near it's limit (10.5A max vs 8.3A). And oh, the insertion force is so, so much higher than ever before. Previous PCIe connectors push about 4A through a connector designed for about 13A. Worth also mentioning that the same time the 12VHPWR connector was being market tested was during Ampere, the same generation where Nvidia doubled down on the industrial design of their 1st party cards. Also there's zero devices out there that actually deliver or take 240W over USB-C. Texas Instruments literally only released the datasheets for a pivotal supporting IC within the last 6 months.
- michaelt 2y ago
  > Nobody thought that they could push 50A at 12V through half the connector. If you're saying that the connector doesn't have a 2x safety factor then I'd agree, sure. But I can see how the connector passed through the design reviews, for the 40x0 era cards. The cables are thick enough. The pins seem adequate, especially assuming any GPU that's drawing maximum power will have its fans producing lots of airflow; plenty of connectors get a little warm. There's no risk of partial insertion, because the connector is keyed, and there's a plastic latch that engages with a click, and there's four extra sense pins. I can see how that would have seemed like a belt-and-braces approach. Obviously after the first round of melted connectors they should have fixed things properly. I'm just saying to me this seems like regular negligence, rather than gross negligence.
- crote 2y ago
  > Also there's zero devices out there that actually deliver or take 240W over USB-C. Texas Instruments literally only released the datasheets for a pivotal supporting IC within the last 6 months. The 16-inch Framework laptop can take 240W power. For chargers, the Delta Electronics ADP-240KB is an option. Some Framework users have already tried the combination.
kersplody 2y ago
The connector could reasonably be shrunk. It just now has essentially no design margin so any minor issue immediately becomes major! 50A DC is serious current to be treated with respect. 5A DC is sanely manageable.
Miraste 2y ago
The spec may say it, but I've never encountered a USB-C cable that claims to support 240 watts. I suspect if machines that tried to draw 240W over USB-C were widespread, we would see a lot of melted cables and fires. There are enough of them already with lower power draw charging.
- DebtDeflation 2y ago
  Search Amazon for "240W USB" and you get multiple pages of results for cables. A few years ago there was a recall of OnePlus cables that were melting and catching fire, I had 2 of them and both melted. But yes 240W/48V/5A is insane for a spec that was originally designed for 0.5W/5V/100mA. I suspect this is the limit for USB charging as anything over 48V is considered a shock hazard by UL and 5A is already at the very top of the 3-5A limit of 20AWG for fire safety.
  - makeitdouble 2y ago
    We've had a variety of 140W laptops for a few years already, so the original spec has been far away for a while now. The advantage of USB-C is the power negotiation, so getting the higher rating only on circuits that actually support it should de doable and relatively safe. The OnePlus cable melting give me the same impression as when hair power cables melt: it's a solved problem, the onus is on the maker.
- makeitdouble 2y ago
  240W cables are here but at around a 10x price premium. Also cables are chipped so e.g. a 100W cable won't allow 240 in the first place. Users needing the 240W have a whole chain of specialized devices, so buying a premium cable is also not much of an issue.

baq 2y ago

At these wattages just give it its own mains plug.

Joker_vD 2y ago
Also put it in a separate case, and give it an OcuLink cable to attach to the main desktop tower. I suspect that's exactly where we're heading, to be fair.
- dylan604 2y ago
  I've built video rigs that did just that. An external expansion chassis that you could put additional PCIe cards when the host only had 3 slots. The whole eGPU used to be a cute thing, but it might have been more foreshadowing than we realized.
  - fooker 2y ago
    Have you measured latency? In modern(last 4 years approximately) GPUs, physical wiring distance is starting to contribute substantially to latency.
    - dylan604 2y ago
      There were no latency concerns. These were video rigs, not realtime shoot'em ups. They were compute devices running color correction and other filters type of thing, not pushing a video signal to a monitor 60fps 240Hz refresh nonsense. These did real work /s
      - fooker 2y ago
        Ah makes sense, the other kind of graphics!
    - KeplerBoy 2y ago
      latency due to wiring distances is far from being an issue in these scenarios. The signals travel at the speed of light. 186 miles per millisecond. The problem you will encounter with pcie gen5 risers is signal integrity.

short_sells_poo 2y ago

This is the top end halo product. What's wrong with pushing the envelope? Should we all play tetris because "what's wrong with block graphics?". I'm not defending the shitty design here, but I'm all for always pushing the boundaries.

KeplerBoy 2y ago
Pushing the boundaries of a simple connector is not innovation, that's just reckless and a fire hazard.

deleted 2y ago

[deleted]

mschuster91 2y ago

> If only we had connectors which could actually handle such currents. The problem isn't connectors, the problem (fundamentally) is to share electric connectivity between multiple conductors. Sure, you can run 16A over 1.5 mm² wires, and 32A over 2.5 mm² (taken from [1], yes it's for 230V but that doesn't matter, the current is important not the voltage). And theoretically you could run 32A over 2x 1.5 mm² (you'd end up with 3 mm² cross section), but it's not allowed by code as when, for any reason, either of the two legs disconnects entirely or has increased resistance e.g. due to corrosion or a loose screw / wire nut (hence, please always use Wago style clamps - screws and wire nuts are not safe, even if torqued properly which most people don't), suddenly the other leg has to carry (much) more current than it's designed for and you risk anything from molten connectors to an outright fire. And that is what NVidia currently is running into, together with bad connections (e.g. due to dirt ingress). The correct solution would be for the GPU to not tie together the incoming individual 12VHPWR pins on a single plane right at the connector input but to use MOSFETs and current/voltage sense to detect stuff like different current availability (at least it used to be the case with older GPUs that there were multiple ways to supply them with power and only, say, one of two connectors on the GPU being used) or overcurrents due to something going bad. But that adds complexity and, at least for the overcurrent protection, yet another microcontroller plus one ADC for each incoming power pin. Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry. Another and even more annoying issue by the way is grounding - because all the electricity that comes in also wants to go back to the PSU and it can take any number of paths - the PCIe connector, the metal backplate, the 12VHPWR extra connector, via the shield of a DP cable that goes to a Thunderbolt adapter card's video input to that card, via the SLI connector to the other GPU and its ground... Electricity is fun! [1] https://stex24.com/de/ratgeber/strombelastbarkeit https://stex24.com/de/ratgeber/strombelastbarkeit

Dylan16807 2y ago
> The correct solution would be for the GPU to not tie together the incoming individual 12VHPWR pins on a single plane right at the connector input but to use MOSFETs and current/voltage sense to detect stuff like different current availability (at least it used to be the case with older GPUs that there were multiple ways to supply them with power and only, say, one of two connectors on the GPU being used) or overcurrents due to something going bad. But that adds complexity and, at least for the overcurrent protection, yet another microcontroller plus one ADC for each incoming power pin. > Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry. So as you say, monitoring multiple inputs happened on the older xx90s, and most cards still do it. It's not hard. Multiple DC-DC converters is something every GPU has. That's the only way to get enough current. So all you have to do is connect them to specific pins.