Bolt Graphics, a GPU startup from Sunnyvale, California, this week introduced its Zeus GPU platform that is designed for gaming, rendering, and supercomputer simulations. The company says that its Zeus GPU not only supports features like upgradeable memory and built-in Ethernet interfaces, but it can also beat Nvidia's GeForce RTX 5090 by around 10 times in path tracing workloads, according to slide published by ServeTheHome. There is one major catch: Zeus can only beat the RTX 5090 GPU in path tracing and FP64 compute workloads because it does not support traditional rendering techniques. This means it has little of no chance to become one of the best graphics cards.
RISC-V multi-chiplet GPU
Unlike GPUs from AMD, Intel, and Nvidia that rely on proprietary instruction set architectures, Bolt's Zeus relies on the open-source RISC-V ISA, according to slides published by ServeTheHome. The Zeus core relies on an open-source out-of-order general-purpose RVA23 scalar core mated with FP64 ALUs and the RVV 1.0 (RISC-V Vector Extension Version 1.0) that can handle 8-bit, 16-bit, 32-bit, and 64-bit data types as well as Bolt's additional proprietary extensions designed for acceleration of scientific workloads.
As Zeus is aimed at path tracing rendering technique as well as compute workloads, it does not seem to have traditional fixed-function GPU hardware like texture units (TMUs) and raster operation units (ROPs), so it has to rely on compute shaders (or similar methods) for texture sampling and graphics outputs. This saves precious silicon real estate for compute elements. Nonetheless, each Zeus GPU has one DisplayPort 2.1a and one HDMI 2.1b output.
Like many processors these days, Zeus relies on a multi-chiplet design. The entry-level Zeus 1c26-032 features a single processing unit that is equipped with 32 GB of LPDDR5X memory at 273 GB/s and can be mated with up to 128 GB of DDR5 memory using two SO-DIMMs (at 80 GB/s). The Zeus GPU is also paired with an I/O chiplet that packs a QSFP-DD port for 400GbE/800GbE, two PCIe Gen5 x16 slots with CXL 3.0 on top (enabling efficient memory sharing across multiple cards), and a GbE port for BMC. The GPU chiplet connects to its I/O chiplet at 256 GB/s.
The more advanced Zeus 2c26-064/128 uses two Zeus processing units, an I/O chiplet, and supports either 64 GB or 128 GB of LPDDR5X memory. The most powerful — Zeus 4c26-256 — implementation integrates four processing units, four I/O chiplets, 256 GB LPDDR5X and up to 2 TB of DDR5 memory. The quad-chiplet Zeus implementation is not a card, but rather is a server.
Unlike high-end GPUs that prioritize bandwidth, Bolt is evidently focusing on greater memory size to handle larger datasets for rendering or simulations. Also, built-in 400GbE and 800GbE ports to enabling faster data transfer across networked GPUs indicates datacenter focus of Zeus.
Performance
High-quality rendering, real-time path tracing, and compute are key focus areas for Zeus. As a result, even the entry-level Zeus 1c26-32, offers significantly higher FP64 compute performance than Nvidia's GeForce RTX 5090 — up to 5 TFLOPS vs. 1.6 TFLOPS — and considerably higher path tracing performance: 77 Gigarays vs. 32 Gigarays. Zeus also features larger on-chip cache than Nvidia's flagship — up to 128 MB vs. 120 MB — and lower power consumption: 120W vs. 575W, making it more efficient for simulations, path tracing, and offline rendering.
However, the RTX 5090 dominates in AI workloads with its 105 FP16 TFLOPS and 1,637 INT8 TFLOPS compared to 10 FP16 TFLOPS and 614 INT8 TFLOPS offered by single-chiplet Zeus. If Zeus could do traditional rendering, then the 1c26-32 with with its 10 FP32 TFLOPS performance would have no chance against the RTX 5090's 105 TFLOPS.
The quad-chiplet 4c26-256 — which still consumes less power than the GeForce RTX 5090, but is likely to be more expensive — can beat Nvidia's gaming flagship in all workloads except FP32 and FP16, which emphasizes that traditional gaming was not the priority. The company indicates that the quad-chiplet variant is optimized for electromagnetic field modeling, photonics research, and FFT calculations. With its larger memory pools and reduced reliance on external storage, Zeus promises to improve speed of large-scale simulations. Assuming, of course, that its hybrid memory subsystem works efficiently across all workloads.
Software
Software support will be a critical factor in the success of Bolt's Zeus GPUs, as hardware capabilities alone are not enough to compete with established players like AMD and Nvidia. Unlike CUDA for Nvidia and ROCm for AMD, Bolt's Zeus lacks a mature, widely adopted software ecosystem. Since it is based on RISC-V, Zeus can potentially leverage existing open-source tools and libraries, but without strong developer support, adoption will be limited.
One thing that Bolt introduced is its Glowstick path tracing rendering engine, which could be a promising in-house solution for real-time rendering. Traditional rendering workflows require long processing times to visualize changes, whereas Zeus significantly reduces this delay, which makes it useful for professional visualization applications. Compared to existing solutions, Bolt claims up to 2.5x faster performance on single-chip variants, scaling higher with multiple GPUs.
However, it is unclear whether Zeus can support industry-standard frameworks such as OpenCL, Vulkan, and CUDA-translation layers, which are essential for gaining traction in HPC workloads. If Bolt Graphics provides strong developer tools, robust compiler support, and compatibility with Linux-based HPC environments, Zeus could establish itself as a competitor in scientific computing and rendering, but it faces an uphill battle against Nvidia's well-established ecosystem.
Availability
Bolt Graphics says that the first developer kits will be available in late 2025, with full production set for late 2026, which will give time for software developers to play with the hardware.
The number of discrete GPU developers from the U.S. and Western Europe has shrunken to three companies in 2025 from around 10 in 2000. Nvidia dominates the market and is followed by AMD and Intel, which can compete in select segments only. No company in the recent years — at least outside of China — was bold enough to engage into competition against these three contenders, so the very emergence of Bolt Graphics seems like a breakthrough. However, the major focuses of Bolt's Zeus are high-quality rendering for movie and scientific industries as well as high-performance supercomputer simulations.
If Zeus delivers on its promises, it could establish itself as a serious alternative for scientific computing, path tracing, and offline rendering. However, without strong software support, it risks struggling against dominant market leaders.
