A new dynamic bandwidth re-allocation technique in optically interconnected high-performance computing systems

As bit rates increase, optical interconnects based high-performance computing (HPC) systems improve performance by increasing the available bandwidth (using wavelength-division multiplexing (WDM) and space-division multiplexing (SDM)) and decreasing power dissipation as compared to traditional electrical interconnects. While static allocation of wavelengths (channels) in optical interconnects provide every node with equal opportunity for communication, it can lead to network congestion for non-uniform traffic patterns. In this paper, we propose an opto-electronic interconnect for designing a flexible, high-bandwidth, low-latency, dynamically reconfigurable architecture for scalable HPC systems. Reconfigurability is realized by monitoring traffic intensities, and implementing dynamic bandwidth re-allocation (DBR) technique that adapts to changes in communication patterns. We propose a DBR technique - Lock-Step (LS) that balances the load on each communication channel based on past utilization. Simulation results indicate that the reconfigured architecture shows 40% increased throughput and and 20% reduced network latency as compared to HPC electrical networks.