BEAM: A Multi-Channel Optical Interconnect for Multi-GPU Systems

High-performance computing and AI applications necessitate high-bandwidth communication between GPUs. Traditional electrical interconnects for GPU-to-GPU communication face challenges over longer distances, including high power consumption, crosstalk noise, and signal loss. In contrast, optical interconnects excel in this domain, offering high bandwidth and consistent power dissipation over long distance. This paper proposes BEAM, a Bandwidth-Enhanced optical interconnect Architecture for Multi-GPU systems. BEAM extends electrical-optical interfaces into the GPU package, positioning them close to GPU compute logic and memory. Unlike existing single-channel approaches, each BEAM optical interface incorporates multiple parallel optical channels, further enhancing bandwidth. An arbitration scheme manages channel usage among data transfers. Evaluation on Rodinia benchmarks and LLM training kernels demonstrates that BEAM achieves a speedup of 1.14 – 1.9× and reduces energy consumption by 29 – 44% compared to the electrical-interconnected system and state-of-the-art schemes, while maintaining comparable chip area consumption.