HyWin: Hybrid Wireless NoC with Sandboxed Sub-Networks for CPU/GPU Architectures

Heterogeneous System Architectures (HSA) that integrate cores of different architectures (CPU, GPU, etc.) on single chip are gaining significance for many class of applications to achieve high performance. Networks-on-Chip (NoCs) in HSA are monopolized by high volume GPU traffic, penalizing CPU application performance. In addition, building efficient interfaces between systems of different specifications while achieving optimal performance is a demanding task. Homogeneous NoCs, widely used for many core systems, fall short in meeting these communication requirements. To achieve high performance interconnection in HSA, we propose HyWin topology using mm-wave wireless links. The proposed topology implements sandboxed heterogeneous sub-networks, each designed to match needs of a processing subsystem, which are then interconnected at second level using wireless network. The sandboxed sub-networks avoid conflict of network requirements, while providing optimal performance for their respective subsystems. The long range wireless links provide low latency and low energy inter-subsystem network to provide easy access to memory controllers, lower level caches across the entire system. By implementing proposed topology for CPU/GPU HSA, we show that it improves application performance by 29 percent and reduces latency by 50 percent, while reducing energy consumption by 64.5 percent and area by 17.39 percent as compared to baseline mesh.