At the heart of 'Data Center Alley' in Northern Virginia, U.S., the world's largest data center cluster, lies Digital Realty's data center 'IAD39' in Ashburn, Loudoun County. This is a mega-scale data center with a power capacity of 96MW (megawatts) and a total floor area of 94,200 square meters. It is 1.7 times the size of Naver's 'Gak Sejong' data center in Sejong City, which has a capacity of 55MW and will be prioritized for operation in the first half of next year.
While Digital Realty's data centers in Korea are vertical in shape, IAD39 is spread out low and long across a wide site. Daniel Romnoski, Director of Solution Engineering at Digital Realty, explained, "The shape of a data center varies depending on the available land and power supply." He added, "In Ashburn, we can secure a wide area, whereas in urban areas, where land is limited, the structure tends to be relatively vertical."
Upon entering the building, a long corridor unfolded, with a kick scooter catching the eye. Given its vast size, employees use it as a means of transportation. Scott Wallace, Senior Vice President of Solution Architecture at Digital Realty, laughed and said, "I sometimes get lost in the corridors myself. I have actually gotten lost in this building several times."
No server noise was audible in the corridor, but when the thick security door opened, the roar emitted by numerous servers and cooling equipment hit the ears. It was a data hall (server room) where customer servers run 24 hours a day. Each space is locked, with cameras installed in various locations. Photography inside the data hall was prohibited.
The power capacity of the data hall entered that day reached 6MW. Numerous server racks were lined up, and cooling equipment operated non-stop. IAD39 has 16 customer spaces (suites) and can accommodate thousands of server racks.
The scale of the cooling equipment that handles heat emitted by servers was also substantial. IAD39 uses air-cooling, which sends cold air under the floor to cool server racks. In a separate machine room, large cooling equipment from Vertiv is lined up. Director Romnoski stated, "The capacity of one cooling unit is approximately 165kW (kilowatts)," and explained, "Other data centers also apply liquid cooling to cope with the heat generated by high-density AI (artificial intelligence) servers."
Outside the building, large container-type backup generators are lined up. Each has an output of 3MW. They are activated if the external power supply is cut off. As AI data centers grow larger, securing necessary equipment in a timely manner has become as important as power.
The total IT load of the approximately 40 data centers operated by Digital Realty in Northern Virginia reaches 1GW (gigawatt). Of this, more than 20 data centers are concentrated in Ashburn alone, operating a capacity of 600MW. IAD39 is considered one of the largest among them. Global customers include major IT companies such as Oracle, IBM, and Meta. The workforce in the Northern Virginia region totals 450 to 500 people, averaging about 20 per data center.
Regarding the construction of AI data centers in Korea, Senior Vice President Wallace emphasized the importance of cooperation between power companies and semiconductor manufacturers. He stated, "Given the rapid pace of technological change, data centers being built now must be able to support semiconductor designs that will emerge over the next 3 to 5 years." He pointed out, "Without sufficient consultation with relevant companies, one could end up building a facility that can only be utilized for just one year."
Ashburn, where data centers have been concentrated for about 30 years, demonstrates that when constructing data centers, long-term design considering not only the securing of GPUs (graphics processing units) but also stable power and cooling, backup power, and next-generation semiconductors is crucial.
[Production Support: Ministry of Culture, Sports and Tourism Public-Centered Communication Activation Project]
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