Virtual Fugaku

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What is “Virtual Fugaku”?

“Virtual Fugaku” is a system that reproduces the software environment of the supercomputer Fugaku on other supercomputers or cloud platforms.

Fugaku—one of the world’s leading supercomputers—owes its achievements not only to its powerful hardware, but also to the rich software environment that has been carefully developed over many years to support researchers’ needs. If this proven software ecosystem could be packaged and deployed with a single action on everyday computing resources or cloud services, users could effectively create “another Fugaku” at their fingertips.

Aiming to reproduce a rich software environment equivalent to "Fugaku" available to "anyone around the world"

By enabling researchers to run the same applications in the same environment wherever they are, Virtual Fugaku can greatly accelerate and broaden research and development activities.

To realize this concept, R-CCS is building a standardized HPC software stack capable of developing and running a wide range of scientific and engineering applications. If supercomputing centers around the world adopt this common software stack, applications built for Fugaku will run on other systems without major modification—an enormous benefit for researchers.

Virtual Fugaku aims to become a shared platform for supercomputers, much like iOS, Android, or Windows for personal devices. Just as smartphone apps run consistently across different models, Virtual Fugaku seeks to bring a world where HPC applications can be used seamlessly and uniformly, with simple, one-touch operation.

Why We Are Building “Virtual Fugaku”

Since its official launch in March 2021, Fugaku has made significant contributions to scientific advancement and the resolution of societal challenges. It is widely regarded as an extremely user-friendly supercomputer, and demand for access has continued to grow. As a result, competition for computing time has intensified.

To broaden access to Fugaku’s value, we are working to provide a new option: Virtual Fugaku.

The supercomputing community has long faced several challenges:

Each system has a different environment, requiring users to spend time learning new interfaces and workflows
Users must rebuild their working environment (data, programs, dependencies) every time they switch systems
System providers must reconstruct software environments almost from scratch whenever hardware is updated, creating a significant operational burden

Virtual Fugaku aims to solve these issues by offering a unified environment across systems. With a common software stack, users can develop and run applications consistently, greatly reducing the complexity of working across multiple supercomputers.

In fact, Virtual Fugaku offers several advantages not always available on Fugaku itself:

Immediate availability according to the user’s schedule
Ability to work with non-public or sensitive data locally
Rapid testing of development results

By using Fugaku and Virtual Fugaku together, researchers and industry users can pursue more flexible and efficient workflows. This is particularly beneficial for industry, where usage patterns and data requirements often differ from academic environments.

Current Status

To realize Virtual Fugaku, we began by targeting CPUs compatible with Fugaku’s A64FX. With support from AWS, we focused on AWS Graviton, an Arm-based CPU widely available on AWS cloud services.

The initial version (v1.0) of Virtual Fugaku was released in August 2024, followed by continuous expansion of its software components. In November 2025, we released the second major version (v2.0).

In v2.0, we significantly improved one of the major challenges of v1.0—the large and unwieldy container size. Users can now select and add only the applications they need, making containers substantially lighter and simplifying downloads and deployment. This allows anyone to assemble a lean HPC environment tailored to their specific research purpose.

The Virtual Fugaku software stack is built from carefully selected open-source applications frequently used on Fugaku itself. As long as Fugaku continues to support active research, we will keep revisiting and updating the software stack. In other words, the software needed to generate cutting-edge scientific results will always remain available globally through Virtual Fugaku.

We provide Singularity container images as the main distribution method. AWS users can install the container image on their AWS instances to create their own “Private Fugaku.” For Fugaku users, we also provide “Satellite Fugaku,” a testbed environment available to all users.

Container images and related documentation are available at the following links:

Future Directions

Virtual Fugaku will continue to evolve as Fugaku’s software environment advances. Our goal is to nurture it as a long-lived, sustainable platform. We will extend its capabilities beyond traditional HPC—for example, to R-CCS initiatives such as AI for Science and quantum computing—and support not only the next-generation supercomputer “Fugaku NEXT” but also emerging computational platforms that will follow.

Virtual Fugaku is designed with the understanding that research purposes and scientific themes constantly evolve—and thus the software required will continue to change as well. Rather than selecting software based on predetermined assumptions, we continuously monitor what researchers actually run on platforms such as Fugaku. By identifying high-utilization software and integrating it accordingly, we update the software stack based on real usage patterns. This user-driven approach ensures that Virtual Fugaku remains a sustainable research platform that continually adapts and improves.

We also hope to grow Virtual Fugaku together with the community. Active use in cutting-edge research reveals new demands and challenges, which in turn drives the platform’s continuous evolution.

In other words, “continued use” and “evolution guided by users” are the forces that carry Virtual Fugaku into the future.

We invite you to explore the container images and the Satellite Fugaku test environment—and to join us in advancing the sustainable evolution of Virtual Fugaku.