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Each system board is equipped with four CPUs (SPARC64™ VIIIfx). In the SPARC64™ VIIIfx, eight cores are integrated per CPU. In terms of power consumption, this board delivers the world's highest level of performance to power use ratio at 2.2 gigaflops per watt.
In addition, the heat generated from CPU and ICC during operation is removed by water cooling, which leads to a reduction in CPU and ICC power consumption and adds to longer component life.
Note: ICC (interconnect controller) is a chip that controls the network (interconnect).
There are nine power supply units in each rack which supply power to the system. They have a fully redundant design for the highest reliability.
This means operations can continue even if one power supply unit fails.
The disk stores the Operating System (OS) that controls the system.
Note: Aside from the internal hard disks, an external storage system for computational data and results is connected to the rack.
For stable operation of densely racked equipment, efficient removal of heat generated during operation is necessary. Therefore, the K computer uses air cooling as well as water cooling.
Optimization of the air flow within the equipment is an important element in achieving high performance.
To create appropriate air flow paths within the rack, the system boards are mounted in a slanted manner.
To exchange data required for computations and computational results with the external storage system, six IO system boards are installed.
These tubes supply water to cool the CPU and ICC. They have sensors that constantly monitor water pressure, temperature and condensation, etc.
The service processor board controls the rack, it performs the initialization of system boards and monitors errors, failures and anomalies. The service processor boards are configured redundantly for higher reliability, and two boards are installed per rack.