A computer comprising a plurality of interconnected processing nodes arranged in a configuration with multiple layers, arranged along an axis, comprising first and second endmost layers and at least one intermediate layer between the first and second endmost layers is provided. Each layer comprises a plurality of processing nodes connected in a ring by an intralayer respective set of links between each pair of neighbouring processing nodes, the links adapted to operate simultaneously. Nodes in each layer are connected to respective corresponding nodes in each adjacent layer by an interlayer link. Each processing node in the first endmost layer is connected to a corresponding node in the second endmost layer. Data is transmitted around a plurality of embedded one-dimensional logical rings with an asymmetric bandwidth utilisation, each logical ring using all processing nodes of the computer in such a manner that the plurality of embedded one-dimensional logical rings operate simultaneously.