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Japan's ARM-Based 'Fugaku' System Now the World's Fastest Supercomputer

Fujitsu and the Riken research institute ended up packing 152,064 A64FX chips into what would become the Fugaku system, which is now the world's fastest supercomputer.

 & Michael Kan Principal Reporter

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For the first time, a machine built with ARM chips has achieved the top ranking as the world’s fastest supercomputer. 

On Tuesday, the Top500 supercomputing organization crowned a new champion: Japan’s “Fugaku” system. Based in Kobe, Japan, the machine is able to achieve 2.8 times the processing power of the previous record holder, the US’ Summit supercomputer. 

The Fugaku system stands out due to its use of ARM processors, which are typically found in smartphones and known for their low power consumption. Past top-performing supercomputers have generally avoided their use, and instead relied on server chips from Intel, AMD, and IBM.  

However, the makers of Fugaku—Fujitsu and Japan’s Riken research institute—opted for ARM-based processors at a time when the chip architecture is trying to gain greater adoption in servers. The effort paved the way for the A64FX, an ARM chip from Fujitsu that features 48 cores built on TSMC’s 7-nanometer fabrication technology. 

the server architecture to the supercomputer (Credit: Top500)

Fujitsu and Riken ended up packing 152,064 A64FX chips into what would become the Fugaku system. As a result, the supercomputer can muster 415.5 petaflops or quadrillion floating point operations per second, with the help of 7.2 million computing cores. (In contrast, the Summit supercomputer only has 2.4 million cores.)

The system is also pretty power-efficient. The Top500 organization ranks the Fugaku ninth in terms of energy efficiency, behind the Summit supercomputer, when measuring the computing operations per watt. (Both machines as a whole, however, still require a ton of power.)

Stats on the Fugaku and Summit supercomputers (Credit: Top500)

The news bodes well for the future of ARM chips, which are currently only in four of the top 500 supercomputers. The vast majority, at 469, use Intel silicon. 

Still, the Fugaku probably won’t hold on to the No. 1 supercomputer ranking for long. The US Department of Energy is planning three new “exascale” supercomputers, each of which will be at least more than two times more powerful when compared to the Fugaku. Expect the first machines to start going online next year using Intel and AMD silicon. 

As for the Fugaku, the Riken institute plans on using the new supercomputer to run virtual simulations, which can test new drug therapies, predict the weather, and research physics projects concerning the evolution of the universe. “In addition, Fugaku is currently being used on an experimental basis for research on COVID-19, including on diagnostics, therapeutics, and simulations of the spread of the virus,” the institute said. The supercomputer will begin operations next April.

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About Our Expert

Michael Kan

Michael Kan

Principal Reporter

My Experience

I've been a journalist for over 15 years. I got my start as a schools and cities reporter in Kansas City and joined PCMag in 2017, where I cover satellite internet services, cybersecurity, PC hardware, and more. I'm currently based in San Francisco, but previously spent over five years in China, covering the country's technology sector.

Since 2020, I've covered the launch and explosive growth of SpaceX's Starlink satellite internet service, writing 600+ stories on availability and feature launches, but also the regulatory battles over the expansion of satellite constellations, fights with rival providers like AST SpaceMobile and Amazon, and the effort to expand into satellite-based mobile service. I've combed through FCC filings for the latest news and driven to remote corners of California to test Starlink's cellular service.

I also cover cyber threats, from ransomware gangs to the emergence of AI-based malware. In 2024 and 2025, the FTC forced Avast to pay consumers $16.5 million for secretly harvesting and selling their personal information to third-party clients, as revealed in my joint investigation with Motherboard.

I also cover the PC graphics card market. Pandemic-era shortages led me to camp out in front of a Best Buy to get an RTX 3000. I'm now following how the AI-driven memory shortage is impacting the entire consumer electronics market. I'm always eager to learn more, so please jump in the comments with feedback and send me tips.

The Best Tech I've Had:

  • My first video game console: a Nintendo Famicom
  • I loved my Sega Saturn despite PlayStation's popularity.
  • The iPod Video I received as a gift in college
  • Xbox 360 FTW
  • The Galaxy Nexus was the first smartphone I was proud to own.
  • The PC desktop I built in 2013, which still works to this day.

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