Energy Efficient Chip-to-Chip Wireless Interconnection for Heterogeneous Architectures

Heterogeneous multichip architectures have gained significant interest in high-performance computing clusters to cater to a wide range of applications. In particular, heterogeneous systems with multiple multicore CPUs, GPUs, and memory have become common to meet application requirements. The shared resources like interconnection network in such systems pose significant challenges due to the diverse traffic requirements of CPUs and GPUs. Especially, the performance and energy consumption of inter-chip communication have remained a major bottleneck due to limitations imposed by off-chip wired links. To overcome these challenges, we propose a wireless interconnection network to provide energy-efficient, high-performance communication in heterogeneous multi-chip systems. Interference-free communication between GPUs and memory modules is achieved through directional wireless links, while omnidirectional wireless interfaces connect cores in the CPUs with other components in the system. Besides providing low-energy, high-bandwidth inter-chip communication, the wireless interconnection scales efficiently with system size to provide high performance across multiple chips. The proposed inter-chip wireless interconnection is evaluated on two system sizes with multiple CPU and multiple GPU chips, along with main memory modules. On a system with 4 CPU and 4 GPU chips, application runtime is sped up by 3.94x, packet energy is reduced by 94.4%, and packet latency is reduced by 58.34% as compared to baseline system with wired inter-chip interconnection.