Full Path Tracing On Ubuntu Powered RISC-V Cores
At the 2025 Ubuntu Summit Bolt Graphics introduced a surprise, their line of Zeus GPUs specifically designed for path tracing workloads. You won’t be seeing the Zeus in a gaming PC, it is specifically designed for video rendering, and it is beast. You can expect 4K path tracing at 120 fps with over 25 samples per pixel from the Zeus 1C, which 3.25 times more impressive than the RTX 5090. There will also be a Zeus 2C and a Zeus 4C, the latter of which is expected to provide 13x the performance of the RTX 5090. These benchmarks used simulated hardware, so they might be a bit exaggerated, but even so those numbers are impressive.
The hardware is indeed RISC-V and uses a Linux stack built off of Ubuntu, with the three variants offering different pools of RAM. The Zeus 1C sports 32 GB of soldered on LPDDR5 RAM with two SODIMM slots to let you expand your VRAM up to 160 GB. The 2C will either have 64GB which can be expanded to 320 GB, or a 128GB variant capable of up to 384 GB. The 4C isn’t in production yet but Bolt Graphics implies you can add up to 2TB of total memory!
In order to keep up with the 725 GB/s of memory bandwidth the Zeus 2C offers, the cards use 400 GbE QSFP-DD networking ports which can be used to connect series of Zeus GPUs together without the need for additional networking equipment. Check out the details at The Register, and follow their link to Jon Peddie’s take on the Zeus if you want to learn even more.
