Open Rack

Open Rack is an Open Compute Project standard for a rack and power delivery architecture as an efficient, scalable alternative to the EIA-310 19-inch rack. It is designed specifically for large-scale cloud deployments.

There are several key design features intended to make equipment more efficient to deploy, support, and operate:

Specification

OpenU

Open Rack rack units, also called OpenU or just OU, measure 48 mm in height and describe how tall a rack or piece of equipment is, similar to U when referring to traditional 19-inch racks. For example, a "2OU server" measures 96 millimetres (3+3⁄4 in) in height.

An Open Rack consists of three modular zones: power, equipment, and cable.

To maintain compatibility with existing server infrastructure, OU cabinets are the same 24-inch (610 mm) external width as conventional server cabinets. However, an OpenU is slightly taller, to improve airflow and cable management.

Power zones

Equipment bay

An equipment bay is 21 inches or 533 millimetres wide. An equipment bay rests on support shelves and blind-mates with the power supply through busbars.

Open Rack Wide

In April 2026, as part of a larger Open Data Center Ecosystem for AI announcement, OCP announced Open Rack Wide (ORW), a specification for large format gear racks beyond the original Open Rack specification.

References

  1. ↑ "Products". Open Compute. Retrieved 2018-02-15.
  2. ↑ https://www.opencompute.org/documents/ocp-orv3-it-gear-design-guide-rev-02-june032024-pdf
  3. ↑ Cliff Grossner (April 29, 2026). "Delivering an Open Data Center Ecosystem for AI". Open Compute Project. Retrieved 2026-07-24.