K computer

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; K received top ranking in all four performance benchmarks at the 2011 HPC Challenge Awards. On 18 June 2012, the TOP500 Project Committee announced that the California-based IBM Sequoia supercomputer replaced K as the world's fastest supercomputer, with a LINPACK performance of 16.325 petaflops. Sequoia is 55% faster than K, using 123% more CPU processors, but is also 150% more energy efficient. K computer held third place in the HPCG benchmark test proposed by Jack Dongarra, with 0.6027 HPCG PFLOPS in November 2018. ==Specifications==

Node architecture The K computer comprised 88,128 2.0 GHz eight-core SPARC64 VIIIfx processors contained in 864 cabinets, for a total of 705,024 cores, manufactured by Fujitsu with 45 nm CMOS technology. Each cabinet contained 96 computing nodes, in addition to six I/O nodes. Each computing node contained a single processor and 16 GB of memory. The computer's water cooling system was designed to minimize failure rate and power consumption. Network The nodes were connected by Fujitsu's proprietary torus fusion (Tofu) interconnect. File system The system adopted a two-level local/global file system with parallel/distributed functions, and provided users with an automatic staging function for moving files between global and local file systems. Fujitsu developed an optimized parallel file system based on Lustre, called the Fujitsu Exabyte File System (FEFS), which is scalable to several hundred petabytes. Power consumption Although the K computer reported the highest total power consumption (9.89 MW the equivalent of almost 10,000 suburban homes) on the June 2011 TOP500 list, it is relatively efficient, achieving 824.6 GFlop/kW. This is 29.8% more efficient than China's NUDT TH MPP (ranked #2 in 2011), and 225.8% more efficient than Oak Ridge's Jaguar-Cray XT5-HE (ranked #3 in 2011). However, K's power efficiency still fell far short of the 2097.2 GFlops/kWatt supercomputer record set by IBM's NNSA/SC Blue Gene/Q Prototype 2. For comparison, the average power consumption of a TOP 10 system in 2011 was 4.3 MW, and the average efficiency was 463.7 GFlop/kW. According to TOP500 compiler Jack Dongarra, professor of electrical engineering and computer science at the University of Tennessee, the K computer's performance equaled "one million linked desktop computers". The computer's annual running costs were estimated at US$10 million. ==K Computer Mae rapid transit station==

On 1 July 2011, Kobe's Port Island Line rapid transit system renamed one of its stations from "Port Island Minami" to "K Computer Mae" (meaning "In front of K Computer") denoting its vicinity. In June 2021, after the decommissioning of K computer, the station was renamed as Keisan Kagaku Center Station. ==See also==