Horizon Robotics Unveils Fourth-Generation BPU Architecture “Riemann,” Delivering a 10× Performance Boost
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Horizon Robotics’ launch of its fourth-generation BPU architecture “Riemann,” delivering major leaps in performance and efficiency for autonomous driving and next-generation robotics.
On December 8, 2025, at the Horizon Robotics Technology Ecosystem Conference, Founder and CEO Yu Kai announced the official release of the company’s fourth-generation BPU architecture, named “Riemann” (in tribute to mathematician Bernhard Riemann). Leveraging high-dimensional data–to–low-dimensional optimization algorithms and architectural innovations, Riemann delivers four major advantages:
- 10× improvement in core operator performance,
- 10× increase in the number of supported high-precision operators,
- full-float computation support from Tensor → Vector,
- 5× energy-efficiency improvement for large language model workloads.
The new architecture will be fully integrated into the Journey 7 chip series going forward.
Yu Kai highlighted the evolution of Horizon’s BPU architecture—from Bernoulli (2016) to Bayes (2018) to Nash (2021)—each step aligned with key advances in autonomous driving. The new Riemann architecture aims to become the ultimate compute foundation for general-purpose robotics, capable of handling complex pipelines from perception to prediction to decision-making.
On the same day, Horizon also announced that its compiler OpenExplorer “Tiangong Kaiwu” has been upgraded to version 4.0, marking its entry into the AI-based compilation era. The new version supports multiple Transformer variants, and thanks to faster compilation, enables 20% performance optimization for models.
In addition, Horizon revealed that city-level assisted driving based on a single Journey 6M chip is nearing mass production, targeting vehicles in the US$14,000 price segment. Initial partnerships will include two collaboration models: chip-toolchain partners (Bosch, Joywise, etc.) and algorithm-service partners (Denso, CoRe Driving, etc.).
