The Open Compute Project has released a design guide for Open Rack, its open source hardware project that seeks to establish a new standard for rack design for hyperscale data center environments. The design guide (PDF) provides specifications and guidelines to show suppliers of IT equipment how they can build systems compatible with the Open Rack standard.
Open Rack provides a 21-inch wide slot for servers, expanding upon the 19-inch width that has long been the standard for data center hardware. The wider form factor will create more room for improved thermal management, as well as better connections for power and cabling. One of the key innovations is in the power distribution, where Facebook has created a “power shelf” that houses the power supplies, rather than placing them on board the server tray.
With its larger dimensions, Open Rack foregoes the traditional "rack unit" for a 48mm tall section called an OpenU. The design guide outlines specs for a single rack as well as the three-wide "triplet" racks introduced by Facebook for its data center in Prineville, Oregon. Each rack includes several "innovation zones," each sized at 10 OpenUs, to provide a framework for vendor customizations of servers and storage.
For a closer look at the Open Rack concept, check out this video in which Facebook's Matt Corddry introduces us to “Shorty,” a 10U Open Rack prototype that showcases the new power scheme and other innovations.