Rack Unit

A rack unit is often abbreviated as "RU" or just "U"; it is the standardized unit of measurement used in server racks, as defined by the Electronic Industries Alliance (EIA). "1U" equals the space occupied by three holes on the server rack's mounting flange, which is 44.45 millimeters (or 1.75 inches) of vertical space. A standard 19-inch rack usually measures 42U in height, or about 190 centimeters tall. Since most rack-mounted servers come in the sizes of 1U, 2U, or 4U, the key is to mix and match form factors that will fully populate the rack, while leaving enough room for peripherals such as liquid cooling systems, if required.

In the data-driven age, when most enterprises own their own server rooms or rent rack space in massive data centers, it is imperative to fit as much computational resources as possible in a limited space. Rack units are a convenient way for IT managers to understand how much space is available and how big the servers are. It also helps server manufacturers follow a universal guideline when designing servers, so their products can be installed in server racks around the world.

All of GIGABYTE's server products, including H-Series High Density Servers, G-Series GPU Servers, R-Series Rack Servers, and S-Series Storage Servers, come in standardized form factors ranging from 1U to 5U. This makes it extremely convenient for IT managers to choose the best options based on how much space can be allocated on a server rack. What's more, GIGABYTE has devoted considerable research and development efforts to fit as much computing power as possible in a smaller space. For example, the G291-281 can support up to 8 double-slot GPGPUs or co-processor cards within a 2U form factor—an industry-leading high density design that's nearly unrivalled on the market.

It is worth mentioning that GIGABYTE has introduced revolutionary cooling systems to support high density server designs that also adhere to standard rack unit dimensions. GIGABYTE works with leading cooling solutions providers, such as CoolIT, to provide liquid-cooled systems that utilize heat exchangers designed to fit perfectly in a standard server rack.