5 ms·

most household circuits can only support 15-20 amps at the plug. there will be an upper limit to this and i suspect this is nvidia compromising on TDP in the sh

most household circuits can only support 15-20 amps at the plug. there will be an upper limit to this and i suspect this is nvidia compromising on TDP in the short term to move faster on compute

SequoiaHope 2y ago
I wonder if they will start putting lithium batteries in desktops so they can draw higher peak power.
- jbarrow 2y ago
  There's a company doing that for stovetops, which I found really interesting (https://www.impulselabs.com https://www.impulselabs.com)! Unfortunately, when training on a desktop it's _relatively_ continuous power draw, and can go on for days. :/
  - SequoiaHope 2y ago
    Yeah that stove is what I was thinking of! And good point on training. I don't know what use cases would be supported by a battery, but there's a marketable one I am sure we will hear about it.
- ryao 2y ago
  They already use capacitors for that.
  - SequoiaHope 2y ago
    Batteries and capacitors would serve different functions. Capacitors primarily isolate each individual chip and subsystem on a PCB from high frequency power fluctuations when digital circuits switch or larger loads turn on or off. You would still need to use capacitors for that. The purpose of the batteries would be to support high loads on the order of minutes that exceed the actual wall plug capacity to deliver electricity. I am thinking specifically of the stove linked in your sibling comment, which uses lithium batteries to provide sustained bursts of power to boil a pot of water in tens of seconds without exceeding the power ratings of the wall plug.
    - ryao 2y ago
      It is the same function on different time scales. If you had a big enough capacitor, you could achieve the same thing. Not coincidentally, the capacitors in PSUs are huge, although not battery sized in terms of capacity. The purpose of the capacitors in the PSU is to keep things powered during a power outage to allow for a UPS to switch to battery. The technical term for this is PSU hold up time.
      - SequoiaHope 2y ago
        I consider smoothing out high frequency power fluctuations and providing power over a period of minutes that exceeds the capacity of the wall plug to be conceptually two different functions, even if they have similarities. You’re right that a large enough capacitor could do that, and I’ve worked with high voltage supercapacitor systems which can provide tens of watts for minutes, but the cost is so high that lithium batteries typically make more sense.
Yizahi 2y ago
So you are saying that Nvidia will finally force USA to the 220V standard? :)
- Reason077 2y ago
  Many American homes already have 240V sockets (eg: NEMA 14-30) for running clothes dryers, car chargers, etc. These can provide over 7200W continuous power! I guess PC power supplies need to start adopting this standard.
  - ryao 2y ago
    PC power supplies already support 240V. Their connectors can take 120V or 240V.
    - Reason077 2y ago
      Yes, but a standard household wall socket in the US supplies 120V @ 15A, for a max continuous power of 1.4 kW or so. So typical power supplies are only designed to draw up to that much power, or less. If someone made a PC power supply designed to plug into a NEMA 14-50 you could run a lot of GPUs! And generate a lot of heat!
      - ryao 2y ago
        You just need the right adapters to connect the C14 connector on most PSUs to NEMA 14-50R. Use these two: https://www.amazon.com/IronBox-Electric-Connector-Power-Cords/dp/B07DGM3NXY https://www.amazon.com/IronBox-Electric-Connector-Power-Cord... https://www.amazon.com/14-50P-6-15R-Adapter-Adaptor-Charger/dp/B07HX9JCC4 https://www.amazon.com/14-50P-6-15R-Adapter-Adaptor-Charger/... As long as the PSU has proper overcurrent protection, you could get away with saying it is designed for this. I suspect you meant designed for higher power draw rather than merely designed to be able to be plugged into the receptacle, but your remark was ambiguous. Usually, the way people do things to get higher power draw is that they have a power distribution unit that provides C14 receptacles and plugs into a high power outlet like this: https://www.apc.com/us/en/product/APDU9981EU3/apc-rack-pdu-9000-switched-zerou-11-0kw-230v-21-c13-3-c19/ https://www.apc.com/us/en/product/APDU9981EU3/apc-rack-pdu-9... Then they plug multiple power supplies into it. They are actually able to use the full available AC power this way. A (small) problem with scaling PSUs to the 50A (40A continuous) that NEMA 14-50 provides is that there is no standard IEC connector for it as far as I know. The common C13/C14 connectors are limited to 10A. The highest is C19/C20 for 16A, which is used by the following: https://seasonic.com/atx3-prime-px-2200/ https://seasonic.com/atx3-prime-px-2200/ https://seasonic.com/prime-tx/ https://seasonic.com/prime-tx/ If I read the specification sheets correctly, the first one is exclusively for 200-240VAC while the second one will go to 1600W off 120V, which is permitted by NEMA 5-15 as long as it is not a continuous load. There is not much demand for higher rated PSUs in the ATX form factor most here would want, but companies without brand names appear to make ones that go up to 3.6kW: https://www.amazon.com/Supply-Bitcoin-Miners-Mining-180-240V/dp/B08YKCS5SW https://www.amazon.com/Supply-Bitcoin-Miners-Mining-180-240V... As for even higher power ratings, there are companies that make them in non-standard form factors if you must have them. Here is one example: https://www.infineon.com/cms/en/product/promopages/AI-PSU/#12-kw-solution- https://www.infineon.com/cms/en/product/promopages/AI-PSU/#1...

most household circuits can only support 15-20 amps at the plug. there will be an upper limit to this and i suspect this is nvidia compromising on TDP in the short term to move faster on compute

SequoiaHope 2y ago

I wonder if they will start putting lithium batteries in desktops so they can draw higher peak power.

jbarrow 2y ago
There's a company doing that for stovetops, which I found really interesting (https://www.impulselabs.com https://www.impulselabs.com)! Unfortunately, when training on a desktop it's _relatively_ continuous power draw, and can go on for days. :/
- SequoiaHope 2y ago
  Yeah that stove is what I was thinking of! And good point on training. I don't know what use cases would be supported by a battery, but there's a marketable one I am sure we will hear about it.
ryao 2y ago
They already use capacitors for that.
- SequoiaHope 2y ago
  Batteries and capacitors would serve different functions. Capacitors primarily isolate each individual chip and subsystem on a PCB from high frequency power fluctuations when digital circuits switch or larger loads turn on or off. You would still need to use capacitors for that. The purpose of the batteries would be to support high loads on the order of minutes that exceed the actual wall plug capacity to deliver electricity. I am thinking specifically of the stove linked in your sibling comment, which uses lithium batteries to provide sustained bursts of power to boil a pot of water in tens of seconds without exceeding the power ratings of the wall plug.
  - ryao 2y ago
    It is the same function on different time scales. If you had a big enough capacitor, you could achieve the same thing. Not coincidentally, the capacitors in PSUs are huge, although not battery sized in terms of capacity. The purpose of the capacitors in the PSU is to keep things powered during a power outage to allow for a UPS to switch to battery. The technical term for this is PSU hold up time.
    - SequoiaHope 2y ago
      I consider smoothing out high frequency power fluctuations and providing power over a period of minutes that exceeds the capacity of the wall plug to be conceptually two different functions, even if they have similarities. You’re right that a large enough capacitor could do that, and I’ve worked with high voltage supercapacitor systems which can provide tens of watts for minutes, but the cost is so high that lithium batteries typically make more sense.

Yizahi 2y ago

So you are saying that Nvidia will finally force USA to the 220V standard? :)

Reason077 2y ago
Many American homes already have 240V sockets (eg: NEMA 14-30) for running clothes dryers, car chargers, etc. These can provide over 7200W continuous power! I guess PC power supplies need to start adopting this standard.
- ryao 2y ago
  PC power supplies already support 240V. Their connectors can take 120V or 240V.
  - Reason077 2y ago
    Yes, but a standard household wall socket in the US supplies 120V @ 15A, for a max continuous power of 1.4 kW or so. So typical power supplies are only designed to draw up to that much power, or less. If someone made a PC power supply designed to plug into a NEMA 14-50 you could run a lot of GPUs! And generate a lot of heat!
    - ryao 2y ago
      You just need the right adapters to connect the C14 connector on most PSUs to NEMA 14-50R. Use these two: https://www.amazon.com/IronBox-Electric-Connector-Power-Cords/dp/B07DGM3NXY https://www.amazon.com/IronBox-Electric-Connector-Power-Cord... https://www.amazon.com/14-50P-6-15R-Adapter-Adaptor-Charger/dp/B07HX9JCC4 https://www.amazon.com/14-50P-6-15R-Adapter-Adaptor-Charger/... As long as the PSU has proper overcurrent protection, you could get away with saying it is designed for this. I suspect you meant designed for higher power draw rather than merely designed to be able to be plugged into the receptacle, but your remark was ambiguous. Usually, the way people do things to get higher power draw is that they have a power distribution unit that provides C14 receptacles and plugs into a high power outlet like this: https://www.apc.com/us/en/product/APDU9981EU3/apc-rack-pdu-9000-switched-zerou-11-0kw-230v-21-c13-3-c19/ https://www.apc.com/us/en/product/APDU9981EU3/apc-rack-pdu-9... Then they plug multiple power supplies into it. They are actually able to use the full available AC power this way. A (small) problem with scaling PSUs to the 50A (40A continuous) that NEMA 14-50 provides is that there is no standard IEC connector for it as far as I know. The common C13/C14 connectors are limited to 10A. The highest is C19/C20 for 16A, which is used by the following: https://seasonic.com/atx3-prime-px-2200/ https://seasonic.com/atx3-prime-px-2200/ https://seasonic.com/prime-tx/ https://seasonic.com/prime-tx/ If I read the specification sheets correctly, the first one is exclusively for 200-240VAC while the second one will go to 1600W off 120V, which is permitted by NEMA 5-15 as long as it is not a continuous load. There is not much demand for higher rated PSUs in the ATX form factor most here would want, but companies without brand names appear to make ones that go up to 3.6kW: https://www.amazon.com/Supply-Bitcoin-Miners-Mining-180-240V/dp/B08YKCS5SW https://www.amazon.com/Supply-Bitcoin-Miners-Mining-180-240V... As for even higher power ratings, there are companies that make them in non-standard form factors if you must have them. Here is one example: https://www.infineon.com/cms/en/product/promopages/AI-PSU/#12-kw-solution- https://www.infineon.com/cms/en/product/promopages/AI-PSU/#1...