HPC-Mesh: A Homogeneous Parallel Concentrated Mesh for Fault-Tolerance and Energy Savings

We present the Homogeneous-Parallel-Concentrated-Mesh topology (HPC-Mesh). This NoC topology provides four disjoint homogeneous concentrated mesh networks. The network interface at each core provides connectivity to all these networks by using a novel injection algorithm. Indeed, the topology is dynamically adjusted to the working conditions of the network, minimizing power consumption by using only part of the network for low traffic rates and maximizing performance for high traffic rates by using all the networks. Therefore, the HPC-Mesh is able to adjust itself depending on the traffic demand through an intelligent injection algorithm. We perform comparison against other topologies (always using power and clock gating) with both synthetic traffic and real applications within a complete simulated system. Compared to the 2D-Mesh, on average, we reduce both the execution time by 14% and the energy consumption by 22% in real applications when using 16 cores and up to 24% in execution time and 11% in energy consumption when using 32 cores. Besides, the new topology provides a superior fault tolerance degree. It is able to work when failing up to 3 sub-networks. The extension of the topology to 3D stacked chips is also provided, exhibiting a low and practical resource overhead.