Legendary video game developer imagines a future where GPUs don't need PCs — John Carmack envisions a GPU with Linux onboard, so you would just add power and a display

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The GPU becomes the PC.

John Carmack
(Image credit: John Carmack on X)

Earlier today, legendary video games developer John Carmack, the leader programmer for iconic titles such as Doom, Quake, and Wolfenstein 3D, made the case for what one might casually describe as a standalone graphics card.

Imagine connecting a graphics card to a display and a power source and running diagnostics before installing it or running it standalone later when troubleshooting. Perhaps the card could have a compact Linux distro onboard, mused the iconic Doom developer. It could even come with a handful of apps and utilities and connect to a keyboard via DisplayPort…

Carmack was lamenting the passing of SLI graphics cards on Twitter/X when he went off on a tangent and shared his hopes that GPUs would one day be capable of operating without a host CPU.

“It would just be fun if GPUs made their own video signal with diagnostic information when you apply power outside of a host system,” the video games programming guru wrote. “You could go further and put a tiny Linux system running BusyBox on your command processor, and backchannel keyboard input through the display port if you don’t have a USB port.”

You can tell that the longer Carmack thought about putting an OS on a graphics card, the more he warmed to the idea. And the idea of a standalone computer based upon a graphics card isn’t such a surprising one to push forward in 2024.

It is already quite common for motherboards to be capable of basic functionality without a CPU, for example. Many motherboards have diagnostic lights and/or codes that work regardless of a CPU being present. Also, ‘BIOS Flashback’ is a great modern feature for updating the motherboard BIOS for unsupported new processors and doesn’t need a CPU installed to work. However, BIOS Flashback remains a displayless function in 2024, requiring a dedicated USB port and hardware button. Inevitably, it will develop and may gain display and further functionality.

Moving our focus back to the world of graphics cards, adding M.2 SSD storage to graphics cards seems to be a growing trend. Asus started this ball rolling not that long ago, and GPU-hosted storage was seemingly embraced most recently by Maxsun. A graphics card already has a fair chunk of RAM onboard, even Nvidia models and a modest general processor added to the mix would satisfy all the prerequisites of a classical computer. There are also graphics cards with built-in displays, so even this has already been integrated.

For some enthusiasts and gamers, the GPU is their PC's single largest, most important, and most expensive component. It seems to be primarily because of this that a mini-PC meme is emerging, where users add a PC onto their graphics card rather than a GPU to their PC system. Perhaps that is our destiny, and Carmack predicted it today…

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Mark Tyson
Mark Tyson
News Editor

Mark Tyson is a news editor at Tom's Hardware. He enjoys covering the full breadth of PC tech; from business and semiconductor design to products approaching the edge of reason.

33 Comments Comment from the forums
  • USAFRet
    This negates the term "GPU".

    SOC - System On Chip.
    Everything it needs, on one chip or PCB.
    Reply
  • Kamen Rider Blade
    USAFRet said:
    This negates the term "GPU".

    SOC - System On Chip.
    Everything it needs, on one chip or PCB.
    He basically wants a "LARGE SoC".

    One that is Console-Esque with a HUGE DIE.
    Reply
  • Dr3ams
    "A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (computation)"

    You can call it a desktop, handheld, console or smartphone...but it's still a computer.
    Reply
  • ThisIsMe
    This just sounds like rambling and should never have been put out there for anyone to take seriously. He’s describing something that already exists. He’s just describing a mini PC. Now, one could make the argument that he means he wants a mini PC with more graphics focused computational power vs. the general/IO focused power.
    Reply
  • Sippincider
    Isn't this what we had in the beginning: a processor and a rudimentary OS, handling pixels themselves in shared memory?

    Not saying this is bad, just always interesting when things come full circle. :)
    Reply
  • stuff and nonesense
    Sippincider said:
    Isn't this what we had in the beginning: a processor and a rudimentary OS, handling pixels themselves in shared memory?

    Not saying this is bad, just always interesting when things come full circle. :)
    You beat me to it! Ah the days before graphics acceleration.
    Reply
  • teeejay94
    You talk as if this is some dystopian future we've never seen before, you ever hear of the X3D chips from AMD? that's pretty much as close as you can get to what you're describing, an all in one unit that controls the graphics the processes everything. AMD already did it and I'm an Intel fanboy by definition.
    Reply
  • ezst036
    We did see Doom running on a GPU not all that long ago using only OpenCL - no CPU at all. (and Vulkan)

    Why couldn't the Linux kernel look for OpenCL first and then go from there? Bypassing a CPU and/or not needing one at all fully seems real.

    (I do not mean a SOC, which has an onboard general purpose CPU. It does not appear that Carmack meant a SOC either)
    Reply
  • USAFRet
    ezst036 said:
    We did see Doom running on a GPU not all that long ago using only OpenCL - no CPU at all. (and Vulkan)

    Why couldn't the Linux kernel look for OpenCL first and then go from there? Bypassing a CPU and/or not needing one at all fully seems real.

    (I do not mean a SOC, which has an onboard general purpose CPU. It does not appear that Carmack meant a SOC either)
    And you still need all the other subsystems.

    I/O for kbd/mouse/controller.
    Power from the wall or battery.

    Call it what you want, but it is then no longer 'just a GPU'.
    Reply
  • bit_user
    Kamen Rider Blade said:
    He basically wants a "LARGE SoC".

    One that is Console-Esque with a HUGE DIE.
    No, that's not what he's saying. Go back and read more carefully.

    He doesn't deny the importance of strong CPU cores, for gaming performance, which is something GPUs lack. He's merely pointing out that the cores embedded in current generation GPUs are already general and capable enough that they could at least provide diagnostics without the card having to be plugged into a host system. Since DisplayPort can already tunnel USB, you wouldn't even need to add any new connectors. You just plug in the display cable, the aux power connector, and you should get some kind of basic menu.

    If you think about this sort of capability a bit further, the graphics card could even help you in diagnosing a PC problem. If the graphics card gets powered on without receiving PCIe negotiation from the host CPU, it could show some kind of message like "CPU offline". That would at least save you from staring at a blank screen and wondering whether it's a CPU or GPU problem.

    @USAFRet is right that, when you upgrade the cores inside a GPU so it can be used standalone "in anger", it just turns into an APU like what consoles already have. That's obviously not a new thing and obviously not what he's talking about.
    Reply