18 ms·

Good to see I’m not the only person that’s been thinking about this. Wedging gargantuan GPUs onto boards and into cases, sometimes needing support struts even,

Good to see I’m not the only person that’s been thinking about this. Wedging gargantuan GPUs onto boards and into cases, sometimes needing support struts even, and pumping hundreds of watts through a power cable makes little sense to me. The CPU, RAM, these should be modules or cards on the GPU. Imagine that! CPU cards might be back..

ksec 1y ago
It is not like CPU aren't getting higher wattage as well. Both AMD and Intel have roadmap for 800W CPU. At 50-100W for IO, this only leaves 11W per Core on a 64 Core CPU.
- linotype 1y ago
  800 watt CPU with a 600 watt GPU, I mean at a certain point people are going to need different wiring for outlets right?
  - jchw 1y ago
    At least with U.S. wiring we have 15 amps at 120 volts. For continuous power draw I know you'd want an 80% margin of safety, so let's say you have 1440 Watts of AC power you can safely draw continuously. Power supplies built on MOSFETs seem to peak at around 90% efficiency, but you could consider something like the Corsair AX1600i using gallium nitride transistors, which supposedly can handle up to 1600 watts at 94% efficiency. Apparently we still have room, as long as you don't run anything else on the same circuit. :)
    - cosmic_cheese 1y ago
      Where things get hairy are old houses with wiring that’s somewhere between shaky and a housefire waiting to happen, which are numerous.
      - kube-system 1y ago
        Yeah, but it ain't nothing that microwaves, space heaters, and hair dryers haven't already given a run for their money.
        jchw 1y ago
        Hair dryers and microwaves only run for a few minutes, so even if you do have too much resistance this probably won't immediately reveal a problem. A space heater might, but most space heaters I've come across actually seem to draw not much over 1,000 watts. And even then, even if you do run something 24/7 at max wattage, it's definitely not guaranteed to start a fire even if the wiring is bad. Like, as long as it's not egregiously bad, I'd expect that there's enough margin to cover up less severe issues in most cases. I'm guessing the most danger would come when it's particularly hot outside (especially since then you'll probably have a lot of heat exchangers running.)
      - jchw 1y ago
        As an old house owner, I can attest to that for sure. In fairness though, I suspect most of the atrocities occur in wall and work boxes, as long as your house is new enough to at least have NM sheathed wiring instead of ancient weird stuff like knob and tube. That's still bad but it's a solvable problem. I've definitely seen my share of scary things. I have a lighting circuit that is incomprehensibly wired and seems to kill LED bulbs randomly during a power outage; I have zero clue what is going on with that one. Also, often times opening up wall boxes I will see backstabs that were not properly inserted or wire nuts that are just covering hand-twisted wires and not actually threaded at all (and not even the right size in some cases...) Needless to say, I should really get an electrician in here, but at least with a thermal camera you can look for signs of serious problems.
    - atonse 1y ago
      You can always have an electrician install a larger breaker for a particular circuit. I did that with my "server" area in my study, which was overkill cuz I barely pull 100w on it. But it cost nearly zero extra since he was doing a bunch of other things around the house anyway.
      - davrosthedalek 1y ago
        Larger breaker and thicker wires!
        atonse 1y ago
        I thought you only needed thicker wires for higher amps? Should go without saying, but I am not a certified electrician :-) I only have a PhD from YouTube (Electroboom)
        jchw 1y ago
        The voltage is always going to be the same because the voltage is determined by the transformers leading to your service panel. The breakers break when you hit a certain amperage for a certain amount of time, so by installing a bigger breaker, you allow more amperage. If you actually had an electrician do it, I doubt they would've installed a breaker if they thought the wiring wasn't sufficient. Truth is that you can indeed get away with a 20A circuit on 14 AWG wire if the run is short enough, though 12 AWG is recommended. The reason for this is voltage drop; the thinner gauge wire has more resistance, which causes more heat and voltage drop across the wire over the length of it, which can cause a fire if it gets sufficiently hot. I'm not sure how much risk you would put yourself in if you were out-of-spec a bit, but I wouldn't chance it personally.
        bangaladore 1y ago
        Could you not just run a 240 volt outlet on existing wiring built for 110v? Just send l1 and l2 on the existing hot/neutral?
  - chronogram 1y ago
    That's still not much for wiring in most countries. A small IKEA consumer oven is only 230V16A=3860W. Those GPUs and CPUs only consume that much at max usage anyway. And those CPUs are uninteresting for consumers, you only need a few Watts for a single good core, like a Mac Mini has.
    - dv_dt 1y ago
      So Europe ends up with an incidental/accidental advantage in the AI race?
      - buckle8017 1y ago
        In residential power delivery? yes In power cost? no I'm literally any other way? also no
      - kube-system 1y ago
        Consumers with desktop computers are not winning any AI race anywhere.
      - atonse 1y ago
        All American households get mains power at 240v (I'm missing some nuance here about poles and phases, so the electrical people can correct my terminology). It's often used for things like ACs, Clothes Dryers, Stoves, EV Chargers. So it's pretty simple for a certified electrician to just make a 240v outlet if needed. It's just not the default that comes out of a wall.
        kube-system 1y ago
        To get technical -- US homes get two phases of 120v that are 180 degrees out of phase with the neutral. Using either phase and the neutral gives you 120v. Using the two out of phase 120v phases together gives you a difference of 240v. https://appliantology.org/uploads/monthly_2016_06/large.57581ad8d9a5d_240VACinResidentialPowerSupplies.png.f176ab25d2092125b3d05d648597b1f8.png https://appliantology.org/uploads/monthly_2016_06/large.5758...
  - orra 1y ago
    Laughs in 230V (sorry).
    - AnthonBerg 1y ago
      ʰᵉₕₑheʰᵉₕₑhe in 400V
  - tracker1 1y ago
    There already are different outlets for these higher power draw beasts in data centers. The amount of energy used in a 4u "AI" box is what an entire rack used to draw. Data centers themselves are having to rework/rewire areas in order to support these higher power systems.
  - t0mas88 1y ago
    A simple kitchen top water cooker is 2000W, so a 1500W PC sounds like no big deal.
    - kube-system 1y ago
      Kettles in the US are usually 1500W, as the smallest branch circuits in US homes support 15A at 120V and the general rule for continuous loads is to be 80% of the maximum.
      - linotype 1y ago
        True but kettles rarely run for very long.
        kube-system 1y ago
        But computers do, which was why I included that context. You don't really want to build consumer PC >1500W in the US or you'd need to start changing the plug to patterns that require larger branch circuits.
        CyberDildonics 1y ago
        Kettles and microwaves are usually 1100 watts and lower, but space heaters and car chargers can be 1500 watts and run for long periods of time.
        wtallis 1y ago
        Microwave ovens top out around 1100-1250W output from a ~1500W input from the wall. Apparently there's a fair bit of energy lost in the power supply and magnetron that doesn't make it into the box where the food is.
        Tor3 1y ago
        Microwave ovens have a different issue, which I found when I upgraded my breaker board to a modern one in my house. The startup pulse gives a type of load which trips a standard A-type 10A breaker (230V). Had to get those changed to a "slow" type, but even that will trip every blue moon, and if there's something else significant on the same circuit the microwave oven will trip even so, every two weeks or so (for the record, I have several different types of microwave ovens around the house, and this happens everywhere there's a 10A circuit). The newer circuits in the house are all 16A, but the old ones (very old) are 10A. A real pain, with new TN nets and modern breakers.
  - triknomeister 1y ago
    And cooling. Look here: https://www.fz-juelich.de/en/news/archive/press-release/2025/jupiter-supercomputer-propels-european-computing-power https://www.fz-juelich.de/en/news/archive/press-release/2025... Especially a special PDU: https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-2025/04_jupiter_030-3000.jpg/@@images/image/larger https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-202... And cooling: https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-2025/10_jupiter_035-3000.jpg/@@images/image/larger https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-202...
  - 0manrho 1y ago
    This is a legitimate problem in datacenters. They're getting to the point where a single 40(ish)OU/RU rack can pull a megawatt in some hyperdense cases. The talk of GPU/AI datacenters consuming inordinate amounts of energy isn't just because the DC's are yuge, (although some are), but because the power draw per rack unit space is going through the roof as well. On the consumer side of things where the CPU's are branded Ryzen or Core instead of Epyc or Xeon, a significant chunk of that power consumption is from the boosting behavior they implement to pseudo-artificially[0] inflate their performance numbers. You can save huge (easily 10%, often closer to 30%, but really depends on exact build/generation) on energy by doing a very mild undervolt and limiting boosting behavior on these cpus and keeping the same base clocks. Intel 11th through 14th gen CPU's are especially guilty of this, as are most Threadripper CPU's. you can often trade single digit or even negligible performance losses (depends on what you're using it for and how much you undervolt/underclock/restrict boosting) for double digit reductions in power usage. This phenomenon is also true for GPU's when compared across the enterprise/consumer divide, but not quite to the significant extent in most cases. Point being, yeah, it's a problem in data centers, but honestly there's a lot of headroom still even if you only have your common American 15A@120VAC outlets available before you need to call your electrician and upgrade your panel and/or install 240VAC outlets or what have you. 0: I say pseudo-artificial because the performance advantages are real, but unless you're doing some intensive/extreme cooling, they aren't sustainable or indicative of nominal performance, just a brief bit of extra headroom before your cooling solution heat-soaks and the CPU/GPU's throttle themselves back down. But it lets them put the "Bigger number means better" on the box for marketing.
    - ciupicri 1y ago
      How safe is undervolting? Can it cause stability issues?
      - 0manrho 1y ago
        Far safer than overvolting. Changing settings can lead to stability issues no matter which way you push it frankly. If you're don't know what you're doing/aren't comfortable with it, probably not worth it.
  - esseph 1y ago
    Yes and this is something I've been thinking about for awhile. A computer is becoming a Home Appliance in the it will need 20A wiring and plugs soon, but should move to 220/240v soon anyway (and change the jumper on your standard power supply).
  - nehalem501 1y ago
    It is mostly an issue in countries with 120V mains (I know that in the US 240V outlets exist though). In France for example it is required that standard plugs must be able to deliver at least 16A on each outlet, at the 230V used here, we get 3600W of power, that’s more than enough.
  - jacquesm 1y ago
    You can up the voltage to 240 and re-use the wiring (with some minor mods to the ends), for double the power. Insulation class should be sufficient. That makes good sense anyway. You may still have an issue if the powersupply can't handle 240/60 but for most of the ones that I've used that would have worked. Better check with the manufacturer to be sure though. It's a lot easier and faster than rewiring.
avgeek23 1y ago
And the memory should be a onboard module on the cpu card intel/amd should replicate what apple did with a unified same ringbus sort of memory modules. Lower latency,higher throughput. Would push performance further. Although companies like intel would bleed the consumer dry with, a certain i5-whatever cpu with onboard memory of 16 gigs could be insanely priced compared to what you'd pay for addon memory.
- 0x457 1y ago
  That would pretty much make both intel and amd to start market segmentation by CPU Core + Memory combination. I absolutely do not want that.
sitkack 1y ago
https://en.wikipedia.org/wiki/Compute_Express_Link https://en.wikipedia.org/wiki/Compute_Express_Link
derefr 1y ago
But all of the most-ridiculous hyperscale deployments, where bandwidth + latency most matter, have multiple GPUs per CPU, with the CPU responsible for splitting/packing/scheduling models and inference workloads across its own direct-attached GPUs, providing the network the abstraction of a single GPU with more (NUMA) VRAM than is possible for any single physical GPU to have. How do you do that, if each GPU expects to be its own backplane? One CPU daughterboard per GPU, and then the CPU daughterboards get SLIed together into one big CPU using NVLink? :P
- wmf 1y ago
  GPU as motherboard really only makes sense for gaming PCs. Even there SXM might be easier.
mensetmanusman 1y ago
It’s always going to be a back and forth on how you attach stuff. Maybe the GPU becomes the motherboard and the CPU plugs into it.
db48x 1y ago
No, for a gaming computer what we need is the motherboard and gpu to be side by side. That way the heat sinks for the CPU and GPU have similar amounts of space available. For other use cases like GPU servers it is better to have many GPUs for every CPU, so plugging a CPU card into the GPU doesn’t make much sense there either.

ksec 1y ago

It is not like CPU aren't getting higher wattage as well. Both AMD and Intel have roadmap for 800W CPU. At 50-100W for IO, this only leaves 11W per Core on a 64 Core CPU.

linotype 1y ago
800 watt CPU with a 600 watt GPU, I mean at a certain point people are going to need different wiring for outlets right?
- jchw 1y ago
  At least with U.S. wiring we have 15 amps at 120 volts. For continuous power draw I know you'd want an 80% margin of safety, so let's say you have 1440 Watts of AC power you can safely draw continuously. Power supplies built on MOSFETs seem to peak at around 90% efficiency, but you could consider something like the Corsair AX1600i using gallium nitride transistors, which supposedly can handle up to 1600 watts at 94% efficiency. Apparently we still have room, as long as you don't run anything else on the same circuit. :)
  - cosmic_cheese 1y ago
    Where things get hairy are old houses with wiring that’s somewhere between shaky and a housefire waiting to happen, which are numerous.
    - kube-system 1y ago
      Yeah, but it ain't nothing that microwaves, space heaters, and hair dryers haven't already given a run for their money.
      - jchw 1y ago
        Hair dryers and microwaves only run for a few minutes, so even if you do have too much resistance this probably won't immediately reveal a problem. A space heater might, but most space heaters I've come across actually seem to draw not much over 1,000 watts. And even then, even if you do run something 24/7 at max wattage, it's definitely not guaranteed to start a fire even if the wiring is bad. Like, as long as it's not egregiously bad, I'd expect that there's enough margin to cover up less severe issues in most cases. I'm guessing the most danger would come when it's particularly hot outside (especially since then you'll probably have a lot of heat exchangers running.)
    - jchw 1y ago
      As an old house owner, I can attest to that for sure. In fairness though, I suspect most of the atrocities occur in wall and work boxes, as long as your house is new enough to at least have NM sheathed wiring instead of ancient weird stuff like knob and tube. That's still bad but it's a solvable problem. I've definitely seen my share of scary things. I have a lighting circuit that is incomprehensibly wired and seems to kill LED bulbs randomly during a power outage; I have zero clue what is going on with that one. Also, often times opening up wall boxes I will see backstabs that were not properly inserted or wire nuts that are just covering hand-twisted wires and not actually threaded at all (and not even the right size in some cases...) Needless to say, I should really get an electrician in here, but at least with a thermal camera you can look for signs of serious problems.
  - atonse 1y ago
    You can always have an electrician install a larger breaker for a particular circuit. I did that with my "server" area in my study, which was overkill cuz I barely pull 100w on it. But it cost nearly zero extra since he was doing a bunch of other things around the house anyway.
    - davrosthedalek 1y ago
      Larger breaker and thicker wires!
      - atonse 1y ago
        I thought you only needed thicker wires for higher amps? Should go without saying, but I am not a certified electrician :-) I only have a PhD from YouTube (Electroboom)
        jchw 1y ago
        The voltage is always going to be the same because the voltage is determined by the transformers leading to your service panel. The breakers break when you hit a certain amperage for a certain amount of time, so by installing a bigger breaker, you allow more amperage. If you actually had an electrician do it, I doubt they would've installed a breaker if they thought the wiring wasn't sufficient. Truth is that you can indeed get away with a 20A circuit on 14 AWG wire if the run is short enough, though 12 AWG is recommended. The reason for this is voltage drop; the thinner gauge wire has more resistance, which causes more heat and voltage drop across the wire over the length of it, which can cause a fire if it gets sufficiently hot. I'm not sure how much risk you would put yourself in if you were out-of-spec a bit, but I wouldn't chance it personally.
        bangaladore 1y ago
        Could you not just run a 240 volt outlet on existing wiring built for 110v? Just send l1 and l2 on the existing hot/neutral?
- chronogram 1y ago
  That's still not much for wiring in most countries. A small IKEA consumer oven is only 230V16A=3860W. Those GPUs and CPUs only consume that much at max usage anyway. And those CPUs are uninteresting for consumers, you only need a few Watts for a single good core, like a Mac Mini has.
  - dv_dt 1y ago
    So Europe ends up with an incidental/accidental advantage in the AI race?
    - buckle8017 1y ago
      In residential power delivery? yes In power cost? no I'm literally any other way? also no
    - kube-system 1y ago
      Consumers with desktop computers are not winning any AI race anywhere.
    - atonse 1y ago
      All American households get mains power at 240v (I'm missing some nuance here about poles and phases, so the electrical people can correct my terminology). It's often used for things like ACs, Clothes Dryers, Stoves, EV Chargers. So it's pretty simple for a certified electrician to just make a 240v outlet if needed. It's just not the default that comes out of a wall.
      - kube-system 1y ago
        To get technical -- US homes get two phases of 120v that are 180 degrees out of phase with the neutral. Using either phase and the neutral gives you 120v. Using the two out of phase 120v phases together gives you a difference of 240v. https://appliantology.org/uploads/monthly_2016_06/large.57581ad8d9a5d_240VACinResidentialPowerSupplies.png.f176ab25d2092125b3d05d648597b1f8.png https://appliantology.org/uploads/monthly_2016_06/large.5758...
- orra 1y ago
  Laughs in 230V (sorry).
  - AnthonBerg 1y ago
    ʰᵉₕₑheʰᵉₕₑhe in 400V
- tracker1 1y ago
  There already are different outlets for these higher power draw beasts in data centers. The amount of energy used in a 4u "AI" box is what an entire rack used to draw. Data centers themselves are having to rework/rewire areas in order to support these higher power systems.
- t0mas88 1y ago
  A simple kitchen top water cooker is 2000W, so a 1500W PC sounds like no big deal.
  - kube-system 1y ago
    Kettles in the US are usually 1500W, as the smallest branch circuits in US homes support 15A at 120V and the general rule for continuous loads is to be 80% of the maximum.
    - linotype 1y ago
      True but kettles rarely run for very long.
      - kube-system 1y ago
        But computers do, which was why I included that context. You don't really want to build consumer PC >1500W in the US or you'd need to start changing the plug to patterns that require larger branch circuits.
      - CyberDildonics 1y ago
        Kettles and microwaves are usually 1100 watts and lower, but space heaters and car chargers can be 1500 watts and run for long periods of time.
        wtallis 1y ago
        Microwave ovens top out around 1100-1250W output from a ~1500W input from the wall. Apparently there's a fair bit of energy lost in the power supply and magnetron that doesn't make it into the box where the food is.
        Tor3 1y ago
        Microwave ovens have a different issue, which I found when I upgraded my breaker board to a modern one in my house. The startup pulse gives a type of load which trips a standard A-type 10A breaker (230V). Had to get those changed to a "slow" type, but even that will trip every blue moon, and if there's something else significant on the same circuit the microwave oven will trip even so, every two weeks or so (for the record, I have several different types of microwave ovens around the house, and this happens everywhere there's a 10A circuit). The newer circuits in the house are all 16A, but the old ones (very old) are 10A. A real pain, with new TN nets and modern breakers.
- triknomeister 1y ago
  And cooling. Look here: https://www.fz-juelich.de/en/news/archive/press-release/2025/jupiter-supercomputer-propels-european-computing-power https://www.fz-juelich.de/en/news/archive/press-release/2025... Especially a special PDU: https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-2025/04_jupiter_030-3000.jpg/@@images/image/larger https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-202... And cooling: https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-2025/10_jupiter_035-3000.jpg/@@images/image/larger https://www.fz-juelich.de/en/newsroom-jupiter/images-isc-202...
- 0manrho 1y ago
  This is a legitimate problem in datacenters. They're getting to the point where a single 40(ish)OU/RU rack can pull a megawatt in some hyperdense cases. The talk of GPU/AI datacenters consuming inordinate amounts of energy isn't just because the DC's are yuge, (although some are), but because the power draw per rack unit space is going through the roof as well. On the consumer side of things where the CPU's are branded Ryzen or Core instead of Epyc or Xeon, a significant chunk of that power consumption is from the boosting behavior they implement to pseudo-artificially[0] inflate their performance numbers. You can save huge (easily 10%, often closer to 30%, but really depends on exact build/generation) on energy by doing a very mild undervolt and limiting boosting behavior on these cpus and keeping the same base clocks. Intel 11th through 14th gen CPU's are especially guilty of this, as are most Threadripper CPU's. you can often trade single digit or even negligible performance losses (depends on what you're using it for and how much you undervolt/underclock/restrict boosting) for double digit reductions in power usage. This phenomenon is also true for GPU's when compared across the enterprise/consumer divide, but not quite to the significant extent in most cases. Point being, yeah, it's a problem in data centers, but honestly there's a lot of headroom still even if you only have your common American 15A@120VAC outlets available before you need to call your electrician and upgrade your panel and/or install 240VAC outlets or what have you. 0: I say pseudo-artificial because the performance advantages are real, but unless you're doing some intensive/extreme cooling, they aren't sustainable or indicative of nominal performance, just a brief bit of extra headroom before your cooling solution heat-soaks and the CPU/GPU's throttle themselves back down. But it lets them put the "Bigger number means better" on the box for marketing.
  - ciupicri 1y ago
    How safe is undervolting? Can it cause stability issues?
    - 0manrho 1y ago
      Far safer than overvolting. Changing settings can lead to stability issues no matter which way you push it frankly. If you're don't know what you're doing/aren't comfortable with it, probably not worth it.
- esseph 1y ago
  Yes and this is something I've been thinking about for awhile. A computer is becoming a Home Appliance in the it will need 20A wiring and plugs soon, but should move to 220/240v soon anyway (and change the jumper on your standard power supply).
- nehalem501 1y ago
  It is mostly an issue in countries with 120V mains (I know that in the US 240V outlets exist though). In France for example it is required that standard plugs must be able to deliver at least 16A on each outlet, at the 230V used here, we get 3600W of power, that’s more than enough.
- jacquesm 1y ago
  You can up the voltage to 240 and re-use the wiring (with some minor mods to the ends), for double the power. Insulation class should be sufficient. That makes good sense anyway. You may still have an issue if the powersupply can't handle 240/60 but for most of the ones that I've used that would have worked. Better check with the manufacturer to be sure though. It's a lot easier and faster than rewiring.

avgeek23 1y ago

And the memory should be a onboard module on the cpu card intel/amd should replicate what apple did with a unified same ringbus sort of memory modules. Lower latency,higher throughput. Would push performance further. Although companies like intel would bleed the consumer dry with, a certain i5-whatever cpu with onboard memory of 16 gigs could be insanely priced compared to what you'd pay for addon memory.

0x457 1y ago
That would pretty much make both intel and amd to start market segmentation by CPU Core + Memory combination. I absolutely do not want that.

sitkack 1y ago

https://en.wikipedia.org/wiki/Compute_Express_Link https://en.wikipedia.org/wiki/Compute_Express_Link

derefr 1y ago

But all of the most-ridiculous hyperscale deployments, where bandwidth + latency most matter, have multiple GPUs per CPU, with the CPU responsible for splitting/packing/scheduling models and inference workloads across its own direct-attached GPUs, providing the network the abstraction of a single GPU with more (NUMA) VRAM than is possible for any single physical GPU to have. How do you do that, if each GPU expects to be its own backplane? One CPU daughterboard per GPU, and then the CPU daughterboards get SLIed together into one big CPU using NVLink? :P

wmf 1y ago
GPU as motherboard really only makes sense for gaming PCs. Even there SXM might be easier.

mensetmanusman 1y ago

It’s always going to be a back and forth on how you attach stuff. Maybe the GPU becomes the motherboard and the CPU plugs into it.

db48x 1y ago

No, for a gaming computer what we need is the motherboard and gpu to be side by side. That way the heat sinks for the CPU and GPU have similar amounts of space available. For other use cases like GPU servers it is better to have many GPUs for every CPU, so plugging a CPU card into the GPU doesn’t make much sense there either.