New Supercomputer "ROQUO" for the Quantum-HPC Hybrid Platform Enters Operation — Launching Full-Scale Integration of Quantum Computing and HPC —

The Quantum-HPC Hybrid Platform Division (Director: Mitsuhisa Sato) of the RIKEN Center for Computational Science (hereafter "R-CCS") has installed a new JHPC-quantum GPU supercomputer, "ROQUO", at R-CCS in Kobe and has begun its operation, to accelerate the integration of quantum computing and high-performance computing (HPC).

"ROQUO" is a new computing platform for the Quantum-HPC Hybrid Platform, named after Mount Rokko, the mountain that symbolizes Kobe. It was introduced as part of the NEDO-commissioned project "Research and Development of Quantum-Supercomputers Hybrid Platform for Exploration of Uncharted Computable Capabilities" (JHPC-quantum project) [1] and was built primarily by DTS Corporation as the "Supercomputer for the Quantum-HPC Hybrid Platform" announced on November 18, 2025. Construction has now been completed as planned, and the system has reached the stage of operational launch.

In the High Performance LINPACK (HPL) benchmark measurement [2] conducted as part of operational preparations, "ROQUO" achieved 19.80 petaflops (PFLOPS; 1 peta = 10^15) in double-precision floating-point (FP64) operations.

The name derives from Mount Rokko, which symbolizes Kobe, the city where the system is installed. Just as Mount Rokko is rooted in Kobe and has undergone development together with the city at its foot, the name "ROQUO" was chosen with the wish that the system will contribute to society and research over the long term—as a computing platform of R-CCS and as the core of Japan’s Quantum-HPC Hybrid Platform.

The artwork on the doors of the computer racks is designed with motifs of the ridgeline of Mount Rokko and the sea and sky of Port Island, where the system is located. By visually expressing the geographical and cultural identity of Kobe, it symbolizes that this is a research platform rooted in the region.

"ROQUO" comprises 135 compute nodes equipped with the NVIDIA GB200 NVL4 [3] (540 NVIDIA Blackwell GPUs in total). The nodes are interconnected by NVIDIA Quantum-X800 InfiniBand networking [4], enabling high-speed communication of up to 3.2 terabits per second (Tbps; 1 tera = 10^12), and the adoption of warm-water-cooled servers [5] achieves both high performance and high energy efficiency.

"ROQUO" is among the world’s first systems in full-scale operation to adopt the GB200 NVL4, and—together with "RIKYU" [6], the AI-for-Science supercomputer announced by RIKEN on the same day as this release—it is among the first systems in full-scale operation in Japan to adopt the GB200 NVL4. In contrast to the NVIDIA GB200 NVL72, a 72-GPU configuration specialized for large-scale training and inference of generative AI, the GB200 NVL4 is a 4-GPU configuration designed with HPC (scientific and technical computing) applications also in mind. While retaining the ability to handle AI workloads, its design emphasizes a balance among the FP64 performance heavily used in HPC, flexibility in installation and operation, and cost performance, making it well suited to a research platform that handles diverse workloads with differing computational characteristics.

In addition, NVIDIA Quantum-X800 InfiniBand and the NVIDIA Quantum-X800 switches that constitute this fabric were deployed for the first time in Japan, together with "RIKYU." This realizes the low-latency, high-bandwidth inter-node communication required by the Quantum-HPC Hybrid Platform.

The system is installed at R-CCS in Kobe and is connected, via the SQC Interface [8], which draws on platforms like NVIDIA CUDA-Q to allow the development of hybrid systems of supercomputers and quantum computers including Japan’s flagship supercomputer "Fugaku" [7].

As part of operational preparations, an HPL benchmark measurement was conducted using the entire "ROQUO" system (135 compute nodes, 540 GPUs). The measured performance (Rmax) in double-precision floating-point (FP64) operations reached 19.8 PFLOPS, demonstrating performance that exceeds the design target for the core computing resource of the Quantum-HPC Hybrid Platform.

The NVIDIA Quantum-X800 InfiniBand platform—adopted in Japan for the first time by "ROQUO" together with "RIKYU"—plays a key role in achieving this performance. The Q3400 switches, based on the InfiniBand standard, which support a communication speed of 800 gigabits per second (Gbps) per port, couple the compute nodes with low latency and high bandwidth, efficiently handling the collective communication that HPL requires.

The HPL benchmark is a communication-intensive workload that involves numerous data transfers and synchronization across compute nodes. In "ROQUO," the combination of the latest-generation NVIDIA Grace Blackwell accelerators and the NVIDIA Quantum-X800 InfiniBand fabric forms a system with a well-balanced ratio of computational to communication performance, providing the stable performance required of a computing platform for the Quantum-HPC Hybrid Platform.

With the launch of "ROQUO," the following initiatives will move into full swing:

In addition, "ROQUO" is operated primarily by R-CCS. By directly operating a system with such an advanced configuration—the NVIDIA Grace Blackwell platform and the NVIDIA Quantum-X800 InfiniBand fabric, deployed in Japan for the first time—R-CCS will reliably accumulate, within the organization, the operational expertise needed for next-generation supercomputers.

Through this accumulation of operational experience, R-CCS will improve the efficiency of future supercomputer operations, and the results obtained will also be applied to the next-generation flagship machine "FugakuNEXT" (development codename) [11], currently under development. The knowledge accumulated in this project—including operational know-how for large-scale GPU clusters and demonstration data on energy-saving operation through warm-water cooling—will form a cornerstone of Japan’s next-generation supercomputing.

"ROQUO" was built primarily by DTS Corporation in accordance with the requirements specified by R-CCS. NVIDIA provided the accelerated computing and networking platform; Giga Computing Technology was responsible for the design and manufacture of the compute nodes; and DataDirect Networks provided the high-speed file system. Using these components, ScaleWorX carried out the overall system integration.

Following the start of operations, R-CCS will take the lead in operating the system, making it available to the research community and to industry as the core computing resource of the Quantum-HPC Hybrid Platform. R-CCS will apply to "ROQUO" the operational expertise it has cultivated through operating supercomputers such as "Fugaku," while accumulating and systematizing the new operational knowledge it gains.

The JHPC-quantum project aims to advance hybrid computing technologies that integrate quantum computers with high-performance computing (HPC) systems. In recent years, the integration of GPU-accelerated computing and AI technologies has attracted significant attention, and the deployment of this new GPU supercomputer comes at a particularly opportune time. We expect that this system will contribute to further advances in quantum-HPC hybrid computing and enable the exploration of new application area.

The next era of scientific discovery will be shaped by systems that unite quantum computing and accelerated supercomputing, opening new paths to problems beyond the reach of either technology alone,” said Tim Costa, general manager of industrial engineering and quantum at NVIDIA. “With ROQUO, RIKEN is bringing that vision into operation by connecting NVIDIA GB200 NVL4 systems and NVIDIA Quantum-X800 InfiniBand with Fugaku and quantum computers through its Quantum-HPC Hybrid Platform.

This project is carried out with funding from NEDO (the New Energy and Industrial Technology Development Organization) under the commissioned project "Research and Development of Quantum-Supercomputers Hybrid Platform for Exploration of Uncharted Computable Capabilities" (Project Leader: Mitsuhisa Sato), part of the "Project for Research and Development of Enhanced Infrastructures for Post 5G Information and Communications Systems (JPNP20017)."

"ROQUO" is operated as a computing platform for research and development by the institutions participating in the JHPC-quantum project. In addition, computing resources are planned to be made available to external researchers and users through the test user program run by the project.

Information on the open-call status and application procedures for the test user program will be provided on the “Test User Program” page of the JHPC-quantum project website (https://jhpc-quantum.org/).

RIKEN Center for Computational Science, Computational Science Promotion Division
Email: r-ccs-koho[at]ml.riken.jp
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