Birds Eye View of Interconnection Networks

1. Birds Eye View of Interconnection Networks The Power of Topology The Effect of Network The Grace of Solution

2. Study of Interconnection Networks

3. Classification: Static vs. Dynamic P1 P2 P3 M1 M2 M3 110 111 100 101 010 011 000 001 • Static or Direct • Ring • Mesh • Hypercube • ……… • Dynamic or Indirect: • Bus, • Crossbar, • MIN

4. Line, Ring and Fully Connected Linear Array:the simplest topology.Fully Connected:Direct connection between every pair of processors, Highest cost, Similar to crossbar in some properties.Ring: Each node in the ring is connected to only two other nodes.Chordal Ring: A compromise between Ring and Fully Connected Network.

5. Mesh and Torus Mesh Topology 2D Torus 3D Torus 2D torus: Meshes with ``wraparound'' connections, e.g. the node at the top of the grid has an ``up'' link that connects to the node at the bottom of the grid (also left to right).

6. Hypercube

7. Tree and Star Tree and Star

8. Fat Tree 8 port four paths 4 port PE2 PE5 PE1 PE3 PE4 PE6 PE7 PE8 PE9 PE10 PE11 PE12 PE13 PE14 PE15 PE16 Note that a message going from PE2 to PE5 may choose any one of four paths from the lower left router to the one at the root. This means that all four PE's attached to the lower left router have a path available to them to reach another node.

9. Crossbar switch P0 –> M1 P1 –> M3 P2 –> M2 P3 –> M0 Crossbar switch N*N switches (N processors N memory modules). The switch configures itself dynamically to connect a processor to a memory module.No contention -- Supports N!permutations. Costly, hard to scale, wastes switches for most patterns.

10. Multistage Network : Omega Network p processors and log2 p stages Each stage consists of a perfect shuffle

11. Multistage Network : Butterfly ButterFly Network