Exploring Node Connection Modes in Multi-Rail Fat-tree
Yuyang Wang, Fei Lei, Dezun Dong · 2021
Although using Multi-Rail network is a popular choice for many HPC systems to overcome bandwidth limitations, the influence of connection modes between multi-port nodes and switching network is not well understood so far. This work provides a detailed analysis of different node connection modes in Multi-Rail Fat-tree. To gain a deep understanding of relevant issues, we propose a new parametric family of Multi-Rail Fat-tree called MR-tree, which could cover all balanced node connection modes for Multi-Rail Fat-tree. We evaluate different node connection modes by theoretical analysis and flit level simulation. The results leave open the possibility that optimization of node connection mode can yield better results for Multi-Rail Fat-tree.