Improving parallel system performance by changing the arrangement of the network links

Publication
International Conference on Supercomputing
Date
Links

Abstract

The Midimew network is an excellent contender for implementing the communication subsystem of a high performance computer. This network is an optimal 2D topology in the sense there are no other symmetric direct networks of degree 4 with a lower average distance or diameter. In fact, it reduces the diameter of the well known torus network by approximately √2 . Although the topology was proposed and analyzed a decade ago, the lack of simple deadlock avoidance mechanisms prevented its utilization up to date. This study solved this drawback by applying the Bubble switching mechanism, a low cost deadlock-avoidance strategy developed by the authors. Moreover, by using routing tables we can configure our Virtual Cut-Through adaptive router to implement either a torus or a Midimew network. Thus, we can exploit the topological advantages of Midimew networks by simply changing the disposition of the wrap-around connections of its torus counterpart, without increasing the network implementation cost. To prove this assertion, we have carried out a thorough evaluation, from the hardware cost of the router to the parallel system performance under real loads.