Data Center Overview

A data center is a facility specialized in managing servers equipped with high-capacity high-speed lines, emergency power supply equipment, etc.
In order to provide a safe and comfortable Internet environment, SAKURA internet maintains one of the largest communication line capacities in Japan, and operates its own data center with a high-speed network and robust facilities.

Three bases

Established in three locations: Tokyo, Osaka, and Hokkaido (Ishikari). Higashi Shinjuku, Nishi Shinjuku and Daikanyama in Tokyo, and Dojima in Osaka. Since they are all in the city center, it is excellent for access by public transport. Each data center is interconnected by a line of 10Gbps or more, and for external connection, it connects with multiple IX and major ISPs. Quality is supported by traffic exchange of about 120 companies.


  • One of the highest capacity backbones

    By connecting Tokyo and Osaka with a large number of major ISPs and IX, we make the probability of network failure as close to 0% as possible, and achieve high availability and overwhelming traffic delivery capability.

  • High speed internetwork

    Each date center is connected with a redundant configuration at 10 gigabits or more. In areas where higher throughput is required, load distribution with multi-line connection is performed to achieve high stability and throughput.

  • Advanced facility

    In addition to adopting seismic control, earthquake-resistant construction, and seismic isolation structures that can withstand earthquakes with a seismic intensity in the upper 6 range, we have achieved a high level of facility capabilities required for data centers, such as the installation of a redundant uninterruptible power supply (UPS).

Ishikari Data Center

Ishikari Data Center is one of the largest suburban data centers optimized for cloud computing in Japan. With its open-air cooling system that uses Hokkaidoʼs cool air improving its energy efficiency, its flexibility resulting from the modular design that has been applied everywhere from the building to the equipment, and the economy of scale resulting from its massive size that is 1.1 times the size of Tokyo Dome, Ishikari Data Center showcases overwhelming cost competitiveness.

Making Full Use of Hokkaidoʼs Cool Climates

Open-air cooling systems can be used in Ishikari Data Centerʼs server rooms almost year-round. Buildings 1 and 2 use a “direct open-air cooling method” by taking Hokkaidoʼs cool air into the server room, reducing electricity consumption by roughly 40% in comparison to normal, urban data centers. This demonstrates the world's highest energy efficiency.
The center currently uses three types of air conditioning systems. One is the “ceiling ventilation system” that cools the servers by blowing outside air in from the ceiling of the server room. The second is the “wall ventilation system” that blows outside air into the room from the walls using a giant fan installed at the side. The serversʼ waste heat is vented out through the ceiling to the outside (see image below). The third is the “hot aisle containment system” that uses the compartments in the aisles between the rows of racks to physically separate the cool air supplied to the servers from the hot air emanating from the servers.

Achieving a PUE of 1.0X

By using Hokkaidoʼs cool outside air, we have been able to reduce the amount of time running cooling systems to under a tenth of conventional data centers, achieving a data center energy efficiency rating of PUE 1.0X.

What is PUE?
PUE (Power Usage Effectiveness) is one of the indices used to represent the energy efficiency of a data center. The closer the number is to 1.0, the better.Generally speaking, any value below 2.0 is considered efficient.

Safe, Expansive Location with Low Risk of Earthquakes,
Tsunamis and Liquefaction

At between 0.1 and 3%, the likelihood of an earthquake with a seismic intensity rating of 6 or higher striking the Ishikari region within the next 30 years is low, and as the highest tsunamis reach 4.7 m and building sites are at least 5.5 m over sea level, one could also say that the risk of tsunamis is almost nonexistent. Furthermore, Ishikari Data Center is built with a double structure and the building itself is relatively light, so the risk of liquefaction is also very low. In addition, at 50,000 m², the siteʼs area is 1.1 times that of Tokyo Dome. With 5 buildings holding up to 6,800 racks, the Ishikari Data Center is not only able to leverage economy of scale, but also respond flexibly to the expansion of clientsʼ business.

Modular and Highly Flexible Construction Design

By using several separate buildings rather than one single building, the Ishikari Data Center never required the construction of any large-scale buildings, and can be expanded in response to demand. The server rooms also follow a modular design, with emergency generators and UPS (uninterruptible power supply) units installed in each one, making them scalable in response to demand, just like the buildings. This makes it possible to adopt the latest technologies at any point in time.

The High-voltage Direct Current(HVDC) Power Supply System
from SAKURA internetʼs Ishikari Solar Power Plant

Ishikari Data Centerʼs commercial environment uses a high-voltage direct current power supply system. The use of direct current makes it possible to reduce the number of AC/DC electricity conversions, thereby simultaneously reducing the need for investments in equipment and improving the efficiency of the power supply. In order to make better use of this DC power supply, SAKURA internet built its “SAKURA internet Ishikari Solar Power Plant” in August 2015. By transmitting the electricity directly from the power plant to Ishikari Data Center in DC without converting it to AC and supplying our server rooms with power, we are able to handle the entire process from power generation to supply and consumption by ourselves.

Improvement of Power Efficiency

Conventional AC systems make two AC/DC conversions from AC→DC→AC in the UPS, which is needed to ensure a stable AC current (batteries operate with DC). On top of this, an additional AC/DC conversion takes place in the power unit within the server, making for a total of three AC/DC conversions. As conversions are invariably accompanied by losses in power, the efficiency of AC systems peaks at between 70 and 80%.
On the other hand, the HVDC 12V system used at Ishikari Data Center converts the AC power it receives into HVDC at the PS racks, and then supplies the electricity to the servers all at once in DC. Therefore, it requires only one AC/DC conversion. The high voltage HVDC is reduced to 12V at the centralized power units in the server racks so that the power is transmitted in a safe form to each server. With an overall efficiency rate of 90% or higher, this revolutionary system is significantly more efficient than conventional AC systems.

What is HVDC?
HVDC stands for “High Voltage Direct Current” and refers to electrical power supply systems that use direct current electricity at high voltages. HVDC 12V takes high voltage DC power of over 300V and supplies the power to servers after lowering the voltage to 12V with centralized power units.

Using Energy from Natural Sources

As the operators of a data center that consumes massive amounts of electricity, we felt that we could use renewable energy ourselves without selling it. Therefore, we opened a solar power plant.

Name: SAKURA internet Ishikari Solar Power Plant
Location: Ishikari City, Hokkaido
Area: 5,004 m²
Output: 200 kW
Voltage: 380V
Electricity generated: 210,000 kWh/year

Building 3 that adopted the new air conditioning concept

The big difference with buildings 1 and 2 with the “direct outside air cooling system” is that it adopted a new air conditioning system “indirect outside air cooling system”. The “indirect outside air cooling system”, which cools the refrigerant circulating between the outdoor unit and the air conditioner with outside air to cool the server room, does not introduce outside air into the room, so there is no humidity variation, and no need for dehumidifiers, humidifiers, humidifier water supply, or the like, which enables us to further reduce the running cost. In addition, we have made various improvements to other equipment. Utilizing the experience of operation in buildings 1 and 2, building 3, which made it possible to accommodate up to 1,900 racks, will be the centerpiece of the Ishikari Data Center from now on.

  • Air conditioning of server rooms with less loss

    By adopting ”upper wall blowing method”, both reduction of ventilation loss and work space comfort were achieved.

  • Compatible with installation of large-sized equipment and large-volume carry-in

    In anticipation of bringing in large-scale equipment, our design enables an electric forklift to run from the entrance to the server room.

  • Power distribution with excellent expandability that does not require electrical engineering work

    By fully adopting the bus duct system with a plug-in branch mechanism instead of the conventional cable system, electric engineering work became unnecessary when adding racks, changing supply power, etc., and expendability and flexibility are improved.

About bus duct
It is insulated and covered with band-shaped conductors for conducting electricity and cased with metal, which is superior to general cable systems in robustness, disaster prevention and efficiency. The plug-in branch mechanism makes it easier to lay the power supply from the bus duct to the server rack, and enables the selection of the breaker according to the load capacity.