4 ms·

I think some of the other comments miss an important point. 600W of power draw means that you need 50A of current through those connectors. Or a bunch of transf

I think some of the other comments miss an important point. 600W of power draw means that you need 50A of current through those connectors. Or a bunch of transformers. You can design it around the old 12V standard but why? For reference, the amperage leading into the house is typically around 100A; you only need around 24A for an electric range / oven. 50A at 12V is probably not optimal. Does the old way of building PCIe cards still make sense when the GPU now draws more power than all of the other system components combined? GPU sag (i.e. the card weighs so damn much) is such an issue that one manufacturer actually put a level in their card.[0] The 4090 probably needs three slots just to keep it attached to the motherboard. When someone buys a desktop these days, it's very often because they need a discrete GPU. You buy a dedicated desktop GPU because the thermal envelope of a laptop can't support a card that would draw 600W - even if it were possible to shrink the card into a laptop (or make the laptop big enough to fit the 600W card). The top of the line Intel processors draw in the neighborhood of 150W but that doesn't necessitate going to a different form factor. Future motherboard and south bridge designs should mount the GPU independently of the other components. [0] https://www.tomshardware.com/news/geforce-rtx-4090-has-a-spirit-level-to-prevent-gpu-sagging https://www.tomshardware.com/news/geforce-rtx-4090-has-a-spi...

nordsieck 4y ago
> You can design it around the old 12V standard but why? For reference, the amperage leading into the house is typically around 100A; you only need around 24A for an electric range / oven. 50A at 12V is probably not optimal. In your opinion, if you could force power supply makers to add another voltage rail, which voltage would you pick?
- davrosthedalek 4y ago
  48V is kinda industry standard, and just below "low voltage" thresholds is most jurisdictions (often 50 or 60V). The cards have switching stages anyway, so it's not that much change (but probably means different power transistors)
- xnyan 4y ago
  There's not exactly a right choice of voltage per say, it's more of which tradeoffs you are willing to accept. Nothing is free, and higher voltage means more noisy, complex, and expensive SMPS power supplies. Solving for the problems of higher current, lower voltage DC we use in ATX format supplies today requires higher gauge copper, but the cable run between the GPU and PSU is so shot that the cost of extra copper could very well be less than the increased cost of a higher voltage supply.
dylan604 4y ago
>For reference, the amperage leading into the house is typically around 100A; where is this typical? in my experience, typical is 200A service for residential. is mains service amps dependent on provider/region/etc?
- kube-system 4y ago
  200A is common for newer construction in the US. Many small post-war homes are 100A. It is common to upgrade these homes when it’s time for a new panel.
  - dylan604 4y ago
    I was under the impression it was the transformers on the pole taking distribution levels down to residential levels that limited this current.
    - kube-system 4y ago
      In the US, generally, the transformer sizing and the line from the pole to your house is the utility company’s problem. When an electrician upgrades a service from 100a to 200a, basically they just ensure the parts between the service line and panel is capable of 200a. —- just the home’s wiring. Often, those transformers on the pole have some wiggle room in what they can deliver, and just because you upgraded from 100a to 200a service doesn’t mean you’ll actually see a real world change in usage. You usually don’t. Utility companies can over provision that capacity because not everyone on a street switches on their microwave at the same time, etc.
tomxor 4y ago
Maybe we need to start plugging motherboards into GPU cards and have the GPU supply the motherboard with power.

nordsieck 4y ago

> You can design it around the old 12V standard but why? For reference, the amperage leading into the house is typically around 100A; you only need around 24A for an electric range / oven. 50A at 12V is probably not optimal. In your opinion, if you could force power supply makers to add another voltage rail, which voltage would you pick?

davrosthedalek 4y ago
48V is kinda industry standard, and just below "low voltage" thresholds is most jurisdictions (often 50 or 60V). The cards have switching stages anyway, so it's not that much change (but probably means different power transistors)
xnyan 4y ago
There's not exactly a right choice of voltage per say, it's more of which tradeoffs you are willing to accept. Nothing is free, and higher voltage means more noisy, complex, and expensive SMPS power supplies. Solving for the problems of higher current, lower voltage DC we use in ATX format supplies today requires higher gauge copper, but the cable run between the GPU and PSU is so shot that the cost of extra copper could very well be less than the increased cost of a higher voltage supply.

dylan604 4y ago

>For reference, the amperage leading into the house is typically around 100A; where is this typical? in my experience, typical is 200A service for residential. is mains service amps dependent on provider/region/etc?

kube-system 4y ago
200A is common for newer construction in the US. Many small post-war homes are 100A. It is common to upgrade these homes when it’s time for a new panel.
- dylan604 4y ago
  I was under the impression it was the transformers on the pole taking distribution levels down to residential levels that limited this current.
  - kube-system 4y ago
    In the US, generally, the transformer sizing and the line from the pole to your house is the utility company’s problem. When an electrician upgrades a service from 100a to 200a, basically they just ensure the parts between the service line and panel is capable of 200a. —- just the home’s wiring. Often, those transformers on the pole have some wiggle room in what they can deliver, and just because you upgraded from 100a to 200a service doesn’t mean you’ll actually see a real world change in usage. You usually don’t. Utility companies can over provision that capacity because not everyone on a street switches on their microwave at the same time, etc.

tomxor 4y ago

Maybe we need to start plugging motherboards into GPU cards and have the GPU supply the motherboard with power.