is a
supercomputer
A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instruc ...
developed by and
PEZY Computing, based around ExaScaler's ZettaScaler immersion cooling system.
It was deployed at the
Japan Agency for Marine-Earth Science and Technology (JAMSTEC) Yokohama Institute for Earth Sciences, the same floor where the
Earth Simulator is located. Amid the scandal regarding the development grant, it was removed from JAMSTEC in April 2018.
System

Gyoukou is based on ExaScaler's ZettaScaler-2.x technology which features
liquid immersion cooling system using
Fluorinert
Fluorinert is the trademarked brand name for the line of electronics coolant liquids sold commercially by 3M. As perfluorinated compounds (PFCs), all Fluorinert variants have an extremely high global warming potential (GWP), so should be used with ...
.
Each immersion tank can contain 16 ''Bricks''. A Brick consists of a backplane board, 32
PEZY-SC2
PEZY Computing is a Japanese fabless computer chip design company specialising in the design of manycore processors for supercomputers.
History
PEZY Computing was founded in 2010 and it is headquartered in Tokyo, Japan.
The company's first manyc ...
modules, 4
Intel Xeon D host processors, and 4
InfiniBand
InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency. It is used for data interconnect both among and within computers. InfiniBand is also used ...
EDR cards.
Modules inside a Brick are connected by hierarchical
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as Peripher ...
fabric switches,
and the Bricks are interconnected by InfiniBand.
Each PEZY-SC2 module contains 2048 processing elements (1 GHz design), six
MIPS64 control processors, and 4
DDR4
Double Data Rate 4 Synchronous Dynamic Random-Access Memory (DDR4 SDRAM) is a type of synchronous dynamic random-access memory with a high bandwidth ("double data rate") interface.
Released to the market in 2014, it is a variant of dynamic rando ...
DIMM
A DIMM (Dual In-line Memory Module) is a popular type of memory module used in computers. It is a printed circuit board with one or both sides (front and back) holding DRAM chips and pins. The vast majority of DIMMs are manufactured in compl ...
s (64GB per module as of November 2017).
Performance
With partial configuration, Gyoukou was ranked 69th at 1,677.1
teraflops
Floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance in computing, useful in fields of scientific computations that require floating-point calculations.
For such cases, it is a more accurate measu ...
on the June 2017
TOP500
The TOP500 project ranks and details the 500 most powerful non-distributed computing, distributed computer systems in the world. The project was started in 1993 and publishes an updated list of the supercomputers twice a year. The first of these ...
ranking.
After upgrade to full scale (equivalent of 19.5 immersion tanks) using newer ZettaScaler-2.2 system, it ranked 4th at 19,135.8 teraflops on the November 2017 TOP500 ranking.
At the time of benchmarking, 1984 out of 2048 cores of each PEZY-SC2 were used at 700 MHz clock.
Gyoukou has high energy efficiency, and it ranked 5th at 14.173 gigaflops/watt on the November 2017
Green500
The Green500 is a biannual ranking of supercomputers, from the TOP500 list of supercomputers, in terms of energy efficiency. The list measures performance per watt using the TOP500 measure of high performance LINPACK benchmarks at double-preci ...
energy efficiency ranking.
at the time benchmarked as 19,860,000 "cores" (after an upgrade).
Notes
External links
ExaScaler Inc.PEZY Computing K.K.* {{youtube, _-z8ErBlBSo, Gyoukou Supercomputer leveraging 48V Factorized Power
Supercomputers
Supercomputing in Japan
Japan Agency for Marine-Earth Science and Technology