Broadcast and associative operations on fat-trees

Abstract

This paper analyzes the cost of performing broadcast, product and prefix computation on the ideal fat-tree, a model proposed here to capture distance and bandwidth properties common to a variety of fat-tree networks. Algorithms are developed and analyzed in terms of the capacity of channels at different levels of the fat-tree. Non trivial lower bounds are derived establishing the optimality of our algorithms for a wide range of channel capacities.