The Evolution of Microsoft’s Data Center Design

Microsoft began its data center expansion with a traditional design featuring cabinets housed in a large room and using perforated floor tiles to create a “hot aisle” and “cold aisle” to manage airflow. This approach was an improvement on prior room-level cooling schemes, but still allowed some warm air to recirculate and mix with cool air.

With its Dublin data center ^[1], Microsoft refined its airflow management, creating “server pods” featuring a hot aisle containment system, with the cabinets housed in a fitted opening in a fixed structure. The hot aisle enclosure has a entrance for admin access. The design houses cabinets on a slab rather than a raised floor. Cool outside air enters the facility through intakes on the rooftop air handlers, and then flows through a duct system into the data center.

In a Chicago facility ^[2] opened in 2009, Microsoft used a garage-like lower level optimized for 40-foot shipping containers packed with web servers, while a second story housed traditional raised-floor data center space. The containers plugged into a “power spine” with hookups to electricity, network, and chilled water for the cooling system.

In early 2011, Microsoft deployed a new design in Quincy, Washington ^[3] that replaced shipping containers with highly-customized pre-fabricated modules known as IT-PACs (short for “Pre-Assembled Components”). The  IT-PACs house hundreds of servers (seen at left) which are cooled by fresh air that enters through louvers in the side of the module (visible at right). The concrete building seen in Chicago has been replaced with a lighter steel and aluminum framework, which the company likened to a “tractor shed.”

In Microsoft’s newest data center campus in southern Virginia, the company has showcased a new design in which the protective structure is completely gone, with the pre-fab IT-PAC modules exposed to the elements. The Boydton, Virginia ^[4] facility employs a hybrid design, with some modules housed within larger enclosures, while others are housed outdoors.