4U rack servers are available with up to 60x 3.5" drive bays and accept full height expansion cards.Servers designed to be fixed in a 19" Cabinet are typically described as rack-mount, rack mounted pc, a rack server, rack mountable, or occasionally simply shelf server. The height of a 5U server is 22.25cm high. The depth of a 5U rack server is not so standard. Depending on the type of rack server purchased. Usually a 5U Server is the largest type of Rack Server, Where Expansion or Processing Power is at it's maximum 5U Rackservers are designed with Power and Expansion as the key features.