Microsoft opened its first data center in 1989. Data centers from this era, considered generation 1, employed little to no air flow management; rooms were kept very cool which resulted in PUEs of 2.0 or higher. The original rationale for building these types of data centers was really to consolidate compute resources that were previously distributed across the network. Today, organizations with these types of data centers are struggling because they’re running out of power or space or cooling capacity.
In 2007, Microsoft decided to start building designing and directly operating its own data centers because the cost of maintaining its generation 1 facilities was rising too fast. These generation 2 data centers were primarily about increasing density and accelerating deployment. Unlike the previous generation where equipment was installed into racks piecemeal and was often non-uniform, racks fully populated with blade servers were now deployed and brought online very quickly. Moreover, airflow was now being optimized for the rack instead of the server which improved the efficiency of these data centers considerably, achieving PUEs between 1.4-1.6.
A lot of today’s modern data centers would be considered generation 2 by Microsoft’s standards where high density racks of blade servers are aligned into hot and cold isles in the data center with or without hot isle containment systems.
A year later, Microsoft adopted the concept of containment and starting deploying servers in ISO standard shipping containers. These containers now allowed Microsoft to deploy large quantities of severs very quickly with predictable results because of the uniformity of the equipment in the containers. For example, when a container arrives onsite, it can be fully provisioned and operational within 8 hours. Moreover, by tighly regulating airflow inside the container, increasing the set point temperate, and increasing its use of air and water side economizers, Microsoft was able to improve its efficiency to where these generation 3 containerized data centers are now operating with PUEs between 1.2 and 1.5.
In its latest data center designs, considered generation 4, Microsoft is incorporating all the learning from its previous generations and is now deploying modular data centers where it builds an engineering spine and modules are connected to it in a plug-in-play fashion. With this design, Microsoft is able to reduce its operating expenses because its using adiabatic cooling which works like a swamp cooler to cool the servers inside IT pre-assembled components (IT PACs). This type of cooling is considerably less expensive (and uses less water) than operating chillers because the power is being used to move air rather than chill water. Microsoft is also reducing its capital expenses with this latest design because less of the data center is being set aside for mechanicals like chillers and other supporting equipment. Additionally, the components to build the data center are being supplied by several vendors from around the world. This allows Microsoft to have a just-in-time approach to building data centers where they can quickly add capacity according to demand signals it receives from the service teams.