Improving Scalability in Thermally Resilient Hybrid Photonic-Electronic NoCs

Hybrid photonic-electronic networks-on-chip (HPENoCs) harness the strengths of both photonic and electronic links to meet the stringent demands of bandwidth, power, and latency of many-core systems. Microring resonators (MRRs), fundamental components in on-chip photonic networks, are highly sensitive to thermal variations, which may lead to erroneous optical transmission. Previously, we proposed a thermal-aware fault-tolerant routing technique (TAFT) to address this problem. In this paper, we examine and evaluate the scalability of TAFT as the NoC size grows. Organizing the NoC into different size clusters is a crucial part of TAFT scalability. Given the same number of cores, different cluster sizes can have up to 45% latency difference. The latency, throughput and power consumption are all dependent on cluster size, under similar traffic patterns. Simulation results also show that as the traffic pattern degrades, revising cluster size can yield up to 56% latency improvement.