One of the more unexpected talks at last week’s Ubuntu Summit 25.10 in London was by Antonio Salvemini of Bolt Graphics, who introduced the company’s forthcoming range of Zeus graphics accelerator hardware. These are very unlike any conventional GPUs – or indeed anything else.

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Bolt’s Zeus hardware will use an entirely different model, and we found it refreshing that the company’s How it works page doesn’t mention the dreaded initialism “AI” once. These accelerators are aimed at producing graphics using a specific rendering method called path tracing.

[…] Path tracing is a step further on from simple ray tracing. A few decades ago, ray tracing was a favorite way to demonstrate high-resolution, multi-color computer graphics, taking hours to days to render scenes of shiny spheres.

As Salvemini put it: “The problem with ray tracing is that each light wave only bounces one way. In path tracing, they can bounce anywhere, and you randomly select just some of these paths to display.” Thus, Monte Carlo path tracing (MCPT) – as described in this 2024 UCSD computer graphics lecture [PDF] – uses Monte Carlo simulation, as invented by John von Neumann and Stanislaw Ulam during World War II.