Efficient sharing of optical resources in low-power optical networks-on-chip

With the ever-growing core counts in modern computing systems, networks-on-chip (NoCs) consume an increasing part of the power budget due to bandwidth and power density limitations of electrical interconnects. To maintain performance and power scaling, alternative technologies are required, with silicon photonics being a promising candidate thanks to high-bandwidth, lowenergy data transmission. To get the best of silicon photonics, sophisticated network designs are required to minimize static power overheads. In this paper, we propose Amon, a low-power optical NoC that decreases the number of μRings, wavelengths, and path losses to reduce power consumption. Amon performs destination checking prior to data transmission on an underlying control network, allowing the sharing of optical bandwidth. Compared to a wide range of state-of-the-art optical, hybrid, and electrical NoCs, Amon improves throughput-per-watt by at least 23% (up to 70%), while reducing power without latency overheads on both synthetic and realistic applications. For aggressive optical technology parameters, Amon considerably outperforms all alternative NoCs in terms of power, highlighting its increasing superiority as technology matures.