The Open Rack is the first rack design to diverge from the existing 19″ rack standard, which had its origins in the railroad industry and was later adopted by the recording industry, among others. The 537mm width (about 21 inches) of the chassis has a lot of practical engineering benefits, like improved airflow, greater energy efficiency, and better volumetric efficiency, as there is more space used for IT equipment instead of just air and metal.
The Open Rack is more than just a server cabinet; it’s also an abstraction layer between the server and the rack, like a hardware API. The rack’s modular equipment bay — which contains the compute, storage, and other related hardware — provides a large degree of flexibility when it comes to configuration. The Open Rack design guide provides specifications and guidelines to show suppliers of IT equipment how they can build systems compatible with the Open Rack.„