A low-cost conflict-free NoC for GPGPUs

As integrated circuits are limited by hardware resources, reducing cost while maintaining the performance becomes especially important. In this article, we propose a conflict-free NoC (cfNoC) for the GPGPU request network. The cfNoC eliminates (i) conflicts among different columns by deploying an exclusive subnet for each column, and (ii) conflicts inside the same column by using a token-based mechanism. The elimination of conflicts allows cfNoC to exploit different subnet channel widths to maintain the performance while reducing cost. Compared with a baseline mesh with 1 VC, our work reduces request network area by 22.6% and power by 23.7%. With 2 VCs, cfNoC achieves more than 37.6% power reduction compared to the baseline and the checkboard placement/routing (CP) design. All these benefits do not cause any performance loss.