On the Bisection Width and Expansion of Butterfly Networks

This paper proves tight bounds on the bisection width and expansion of butterfly networks with and without wraparound. Previously it was known that the bisection width of an n-input butterfly with wraparound is n. We show that without wraparound, the bisection width is 2 p 2 , 1n + on :82n. This result is surprising because it contradicts the prior "folklore" belief that the bisection width is nin both cases. We also show that for every set A of k nodes in a butterfly with wraparound there are at least 4 + o1k=logk edges from A to

• Type: Conference
• Year: 1998
• Where: IPPS
• Authors: Claudson F. Bornstein, Ami Litman, Bruce M. Maggs, Ramesh K. Sitaraman, Tal Yatzkar
• Keywords: Bisection Width, Butterfly, Butterfly Networks, Distributed And Parallel Computing, IPPS 1998