Alternative chip architectures are taking some thunder away from Intel's x86 at this week's International Supercomputing Conference in Frankfurt.

China's TaihuLight, which was ranked the world's fastest supercomputer, has a homegrown chip. And the ARM architecture, which dominates mobile-device chips, will appear in Fujitsu's next flagship supercomputer.

The Fujitsu system, called Post-K, will succeed the K computer that is No. 5 on the Top500 list of the world's fastest supercomputers.

Post-K will be installed at the RIKEN Advanced Institute for Computational Science in Japan in 2020. Fujitsu will share more details about the computer on Tuesday during a session at the conference.

The K computer, which delivers 10.5 petaflops of peak performance, uses the Fujitsu-designed SPARC64 VIIIfx processor. for Post-K, Fujitsu will design an ARM chip.

In 2014, Fujitsu said it would use its SPARC Xlfx processor in the next K computer. It's not clear whether that chip will now go into an upgrade to the current K system. Fujitsu has not respond to a request for comment on that point.

The company also sells servers based on SPARC. There's a chance those might also shift to ARM, said Jim McGregor, principal analyst at Tirias Research.

Fujitsu already makes ARM-based microcontrollers and networking chips.

The fundamental shift in processor architecture will require big changes and investments in the silicon, software and customer support, McGregor said.

Fujitsu may have come to the conclusion that SPARC was losing its competitive edge and they had a choice to move to x86, Power or ARM. ARM processors may be the right choice for its Fujitsu's servers, which are built for infrastructure workloads, McGregor said.

"It maybe isn't a big deal to Intel, but it definitely is a notch in the playing field for one of the alternatives [to x86]," McGregor said.

Companies like Google are also looking at x86 alternatives for custom workloads. Google and Rackspace are teaming up to design a server called Zaius based on the Power9 architecture.

Intel dominates the server chip market and went into 99.2 percent of all servers in 2015, according to IDC. Computing vendors see ARM servers as a power-efficient alternative to Intel's Xeon chips but are mostly still in the testing stage. Analysts believe ARM's market share will grow over time.

There is also growing concern around large-scale supercomputers drawing megawatts of power. ARM supercomputers might be a more power-efficient alternative.