AMD says zettascale supercomputers will need half a gigawatt to operate, enough for 375,000 homes

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AMD predicts how supercomputer power consumption will increase.

Stock image of nuclear cooling towers
(Image credit: Shutterstock)

AMD discussed the limiting factors of AI accelerator development at ISC 2025 — notably, the increasing power requirements of these bleeding-edge chips. ComputerBase reports that AMD expects ZettaFLOP-capable supercomputers of the future to require a nuclear power plant's worth of energy to operate.

AMD shared a graph of the projected growth of supercomputer power consumption until 2035. The graph starts between 2010 and 2015, when supercomputers required just 3.2GF/watt to run. The graph then extends (in a straight line) all the way to 2035, when AMD predicts zetta-scale supercomputers will require 2140GF/watt of power, or half a gigawatt of power. The graph assumes a 2x efficiency improvement in AI processor development every 2.2 years.

Memory bandwidth and cooling capacity are supposedly the main actors responsible for increasing power consumption to such highly predicted levels. As AI hardware increases in computational power, memory bandwidth, and datacenter cooling systems must increase to keep up. This creates a snowball effect of ever-increasing power consumption across all areas in a datacenter.

Expounding this problem further is the demand for FP128, FP64, FP16, and FP8 compute capabilities. Even though FP64 and FP128 provide superior accuracy, some workloads are more useful when run in FP16 and FP8. Thus, future AI accelerators will need to be capable of performing lower precision operations.

We are already seeing power consumption skyrocketing with today's latest AI accelerators. Nvidia's B200 has a TDP of 1000W, and AMD's brand-new MI355X sports a 1,400W TDP. By contrast, Nvidia's A100 flagship AI GPU from 5 years ago consumed just 400W of power — less than an RTX 5090.

The U.S. government is hoping to rectify this growing energy situation before it becomes a problem with nuclear power plants. Several big companies, such as Microsoft, are also investing heavily in nuclear fusion to solve their datacenter power problems.

Supercomputers are still firmly in the ExaFLOP range, with the ElCaptain AMD-MI300A-based supercomputer being the fastest supercomputer in the world, currently. However, full-blown AI-datacenter farms are now reaching zettaFLOP (Zettascale) performance — with Oracle being the first to provide a zettascale cloud computing cluster, boasting an army of 131,072 Blackwell GPUs (equating to 2.4 zettaFLOPS of performance).

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Aaron Klotz
Aaron Klotz
Contributing Writer

Aaron Klotz is a contributing writer for Tom’s Hardware, covering news related to computer hardware such as CPUs, and graphics cards.

11 Comments Comment from the forums
  • Notton
    That doesn't sound like a sustainable level of energy demand growth.
    Well, unless all safety bars are removed and you build a 1GW nuclear reactor in 7yrs... every year for however long is necessary to meet demand.
    Reply
  • LolaGT
    We are going to need many of the latest gen fission reactors or we can not meet our power needs goals, not just for super computers/datacenters, but for just general needs.
    By many I mean dozens and dozens of modular reactors. The big reactors will never be built fast enough or in the numbers needed.
    Reply
  • SomeoneElse23
    Fusion is a long way off, as they haven't yet figured out how to create a container that can sustain the reaction and not be destroyed in the process.

    Nuclear fission reactors can do it though. The technology exists to make fission much safer and the technology exists to deal with the leftovers. But it costs money that the industry doesn't want to put it in it.

    You also have the not in my back yard problem.
    Reply
  • A Stoner
    SomeoneElse23 said:
    Fission is a long way off, as they haven't yet figured out how to create a container that can sustain the reaction and not be destroyed in the process.

    Nuclear fusion reactors can do it though. The technology exists to make fusion much safer and the technology exists to deal with the leftovers. But it costs money that the industry doesn't want to put it in it.

    You also have the not in my back yard problem.
    Fission is what we use today, where atoms are broken apart into lighter elements. Fusion is what we want where we fuse atoms together into heavier elements. Otherwise, true.
    Reply
  • A Stoner
    Notton said:
    That doesn't sound like a sustainable level of energy demand growth.
    Well, unless all safety bars are removed and you build a 1GW nuclear reactor in 7yrs... every year for however long is necessary to meet demand.
    There are not that many top of the line super computers. It should not be that hard to keep up with the onsies and twosies that will be built.
    Reply
  • Alex/AT
    And that means it's a stalemate for energy-inefficient applications.
    The same way countries are already imposing mining bans, it will affect those as well.
    Reply
  • George³
    It's that simple. Stop building crazy amounts of computing power. No matter how hard you try, you can't compute the universe. It's not a problem anymore, is it?
    Reply
  • reryro
    SomeoneElse23 said:
    Fission is a long way off, as they haven't yet figured out how to create a container that can sustain the reaction and not be destroyed in the process.

    Nuclear fusion reactors can do it though. The technology exists to make fusion much safer and the technology exists to deal with the leftovers. But it costs money that the industry doesn't want to put it in it.

    You also have the not in my back yard problem.
    You know, providing all these details while simultaneously having it all totally backwards is a tell-tale sign of not having any understanding of what you're saying, but instead merely regurgitating what you've superficially read...
    Reply
  • SomeoneElse23
    A Stoner said:
    Fission is what we use today, where atoms are broken apart into lighter elements. Fusion is what we want where we fuse atoms together into heavier elements. Otherwise, true.
    Ooops. Got my terms reversed. Thanks! :)
    Reply
  • SomeoneElse23
    reryro said:
    You know, providing all these details while simultaneously having it all totally backwards is a tell-tale sign of not having any understanding of what you're saying, but instead merely regurgitating what you've superficially read...
    Actually, I do understand it, quite well.

    It's a matter of getting my terms reversed, either because I was in a hurry, or because I wasn't thinking clearly.

    I'm sure you get everything you say and write correct, though, right? Never reverse your words, or say something completely different than you meant?
    Reply