Cable paths should be as short as possible. After calculating the length of a cable path, select the shortest cable to satisfy the length requirement. When specifying a cable, consider the following:
Bends in the cable path increase the required length of the cable. Rarely does a cable travel in a straight line from connector to connector. Bends in the cable path are necessary, and each bend increases the total length.
Bundling increases the required length of the cables. Bundling causes one or more cables to follow a common path. However, the bend radius is different in different parts of the bundle. If the bundle is large and unorganized, and there are many bends, one cable might experience only the inner radius of bends, while another cable might experience the outer radius of bends. In this situation, the differences of the required lengths of the cables is quite substantial.
If you are routing the InfiniBand cable under the floor, consider the height of the raised floor when calculating cable path length.