Fig.1: The rankings in TOP500 (ranked 42nd) and Green500 (ranked 25th) prove that the ALPS excels in both computing capability and energy efficiency.

The Green500 provides a ranking of the most energy-efficient supercomputers in the world. Its list ranks computers from the TOP500 list of supercomputers in terms of energy efficiency. 

The supercomputer “ALPS” (short for Advanced Large-scale Parallel Supercluster, also nicknamed Windrider) built by the NARL’s National Center for High-performance Computing (NCHC) in cooperation with Acer was ranked the 25th in the Green500 list – June 2011, setting a new record since Taiwan joined the global ranking in the most energy-efficient supercomputers. 

Addressing the energy efficiency issue, the NARL-NCHC has devoted itself not only to advance its high-performance computing capability, but also to improve its energy-saving technology. The rankings in TOP500 (ranked 42nd in June 2011) and Green500 prove that the ALPS excels in both computing capability and energy efficiency.

The ALPS is installed in the NARL-NCHC’s Taichung Branch. To minimize the power consumption from the air-conditioning system, the machine room racks in a hot-aisle/cold-aisle layout. 

This layout separates the intake cold air and the exhaust hot air, and involves lining up server racks in alternating rows with cold air intakes facing one way (cold aisles) and hot air exhausts facing the other (hot aisles). And the PVC curtain is used to maximize airflow dynamics and increase the effectiveness of hot aisle/cold aisle isolation. Furthermore, the built-in in-row cooling system captures hot air rises from the hot aisle, conditions it through a closed refrigerant pipe, and releases back to the cold aisle. The overall design successfully reduces the demand for air conditioning.

Before embarking on the hot aisle/cold aisle setup in the data center, the NARL-NCHC has conducted a hot/cold flow pattern simulation study and determined the ideal placement of the cabinets that allows the cooling system run more efficiently. 

The ALPS in the setup runs at 400.68 Mflops/watt with a power usage effectiveness value of 1.72. And the total electricity consumption of the ALPS is 758.4 kilowatt that is one fifth of traditional supercomputers’ power consumption. These figures translate into an outstanding energy-efficient performance for a non-GPU (graphics processing unit) processor supercluster.