K computer

The K computer – named for the Japanese word "kei" (京), meaning 10 quadrillion (10¹⁶) – is a supercomputer manufactured by Fujitsu, currently installed at the RIKEN Advanced Institute for Computational Science campus in Kobe, Japan. The K computer is based on a distributed memory architecture with over 80,000 computer nodes. It is used for a variety of applications, including climate research, disaster prevention and medical research. The K computer's operating system is based on the Linux kernel, with additional drivers designed to make use of the computer's hardware.

In June 2011, TOP500 ranked K the world's fastest supercomputer, with a computation speed of over 8 petaflops, and in November 2011, K became the first computer to top 10 petaflops. It had originally been slated for completion in June 2012. In June 2012, K was superseded as the world's fastest supercomputer by the American IBM Sequoia; and as of November 2015, K is the world's fourth-fastest computer.

Performance

On 20 June 2011, the TOP500 Project Committee announced that K had set a LINPACK record with a performance of 8.162 petaflops, making it the fastest supercomputer in the world at the time; it achieved this performance with a computing efficiency ratio of 93.0%. The previous record holder was the Chinese National University of Defense Technology's Tianhe-1A, which performed at 2.507 petaflops. The TOP500 list is revised semiannually, and the rankings change frequently, indicating the speed at which computing power is increasing. In November 2011, RIKEN reported that K had become the first supercomputer to exceed 10 petaflops, achieving a LINPACK performance of 10.51 quadrillion computations per second with a computing efficiency ratio of 93.2%. K received top ranking in all four performance benchmarks at the 2011 HPC Challenge Awards.