An Approximate Bufferless Network-on-Chip

Bufferless network-on-chip (NoC) designs have drawn research attention in massively parallel multicore systems via their significant benefits in power and area savings. However, it shows poor throughput and low bandwidth in current bufferless designs due to complex bufferless routing and arbitration. Especially in the NACK-based bufferless network, the network performance will be affected significantly as the network conflicts increased caused by packet retransmissions. To this end, we proposed a novel approximate bufferless network, ABNoC. ABNoC lessens network conflicts and packet retransmissions via an approximate allocation mechanism (AAM) and a packet approximation method. We show that, compared with SCARAB, ABNoC improved the bandwidth up to 1.92 times and achieved 1.2 times faster in runtime. Besides, ABNoC accomplished 83.6% retransmission reduction and 46.7% latency reduction, while maintaining low application error.