According to the Certified Data Centre Professional (CDCP®) Reference Materials, the height of 1 "U" (rack unit) or "RU" (rack unit) is standardized at 1.75 inches, which is equivalent to 44.45 millimeters or 4.445 centimeters. This unit of measurement is globally used to define the internal mounting space in IT and telecommunications racks. Equipment manufacturers specify their devices’ height based on how many “U” the device occupies (for example, a 2U server is 3.5 inches high). The standardization ensures interoperability and planning efficiency within the data center environment.
The "U" (rack unit) system is essential for ensuring that racks and equipment from different manufacturers will fit together properly, facilitating modularity, expansion, and maintenance. The 1.75-inch specification is defined by several industry standards including EIA-310 and is referenced directly in the EPI CDCP training and its official exam preparation guides.
[:, EPI CDCP® Exam Preparation Guide: https://www.epi-ap.com/uploads/file/exam%20prep/english_preparation_guide_cdcp_202003.pdf, EPI Certified Data Centre Professional (CDCP®) Course Content: https://www.epi-ap.com/services/1/3/4/Certified_Data_Centre_Professional_(CDCP), EPI Data Centre Framework: https://www.epi-ap.com/content/31/67/EPI_Data_Centre_Framework, EPI Data Centre Competence Framework: https://www.epi-ap.com/content/31/83/EPI_Data_Centre_Competence_Framework_(EPI-DCCF), EPI CDCP FAQ, Official standards: EIA-310, ]
Submit