John Carmack was a visionary technology pioneer often hailed as a revolutionary in the first-person shooter genre. He's known for his outspoken opinions and bold predictions about the future of PC technology, and his latest comments may be his boldest yet.
John Carmack envisions a future where GPUs can run independently of the host CPU. The legendary programmer behind PC gaming milestones like Commander Keen, Doom, and Quake believes that modern GPUs are becoming so powerful and versatile that they can effectively act as all-in-one "PCs" from a user's perspective.
Carmack shared his unconventional "GPU is PC" concept on X, recalling the glorious days of interlocking GPUs in the Voodoo era. In the era of Voodoo2 graphics cards ruling the roost as the most powerful "3D accelerator," tech-savvy gamers could use a simple cable to connect two graphics cards to significantly boost gaming performance.
Carmack points out that just one cable can double the pixel rate. He recalled how friends would host hardware parties to combine their 3D graphics cards and enjoy faster, smoother gaming experiences. "In 1998, Quake 2 was played at 1280x1024120Hz at 4xAA. If the graphics card had vertex transform capabilities, you could extend motion blur and stereo/VR multi-view rendering," Carmack added.
Rendering engines in modern games rely heavily on a "render-to-texture" process that is not well suited to daisy-chaining multiple GPUs. However, Carmack proposed an alternative: GPUs could be arranged in a "ring" topology and enhanced with explicit transfer operations, allowing 3D rendering and machine learning frameworks to exploit the full potential of this new hardware setup.
The former idSoftware creator believes that as long as there is a "private link", today's GPUs can eventually run completely independent of the host CPU. Carmack believes that resourceful (which translates to extremely wealthy) users can build powerful accelerator chains. In this setup, the GPU generates its own video signals and diagnostic information and accepts power input directly without the need for a traditional PC host system.
These standalone graphics processors have the potential to run a "tiny" Linux operating system on-board, enabling complete computing independence. Input peripherals such as mice and keyboards can be managed through DisplayPort links, providing functionality even when USB ports are not available.
Carmack's vision of a "computing" graphics processor wasn't entirely new. In fact, developers have previously tried, with partial success, to run the original Doom game's code directly on the GPU, rather than relying on the CPU.
Carmack worked at Facebook in his later years, trying to turn the concept of the Metaverse into a reality, and later left the company to pursue other ventures. Most recently, Carmack predicted major AI breakthroughs by 2030, continuing his trend of bold, forward-thinking ideas.