RIKEN Center for Computational Science

Operated by RIKEN. Hosting 5 systems in this dataset, 3 of them currently operational.

Systems hosted: 5
Installed Rmax: 472.3 PFlop/s
Recorded power: 42.56 MW
Cooling: Direct liquid cooling, warm water, Direct water-cooled LSI (pre-cold-plate era)

Facility facts

Power, cooling and efficiency figures for RIKEN Center for Computational Science, each with its own source and date.

Fact	Value	As of	Basis	Source
Cooling	Fugaku uses cold-water cooling with 15 C inlet; chiller plant of 4 absorption chillers (5.98 MW), 3 centrifugal (4.93 MW) and 1 centrifugal (2.46 MW) with cooling towers RIKEN R-CCS slides at the SCA25 energy efficiency workshop; absorption chillers are driven by steam from the gas-turbine cogeneration.	2025-03	Operator stated	ee-workshop.for.lrz.de
Power supplier	Grid supply at 77 kV stepped to 6.6 kV and 200 V, plus on-site gas turbine generators (5 MW x 2) covering 20-25 percent of site consumption and acting as backup RIKEN facility page confirms two 5000 kW-class cogeneration systems.	2025-03	Operator stated	ee-workshop.for.lrz.de riken.jp
Power supplier	Reuses the K computer site's existing cogeneration power plant and high-voltage substation, with electrical equipment expanded for Fugaku	2021	Operator stated	r-ccs.riken.jp
Cooling	Expanded chilled-water plant; Fugaku racks use 9 parts water cooling to 1 part air cooling	2021	Operator stated	r-ccs.riken.jp

Systems at this site

System	Rmax	Power	First operational	Status
ROQUO	19.80 PFlop/s	-	2026-06-19	operational
Fugaku	442.0 PFlop/s	29.90 MW	2020-06	operational
K computer	10.51 PFlop/s	12.66 MW	2011-06	decommissioned
FugakuNEXT	-	-	-	planned
RIKYU	-	-	-	operational

Facility fields are recorded only where a public source states them. Blank means we have not found one, not that the value is zero: an important distinction if you are aggregating power or PUE across sites.