Multiprocessor system-on-chip designs with active memory processors for higher memory efficiency

Memory access latency and memory-related operations are often the performance bottleneck in parallel applications. In this paper, we present a concept of active memory operations which is an on-chip network transaction that operates based on the microcode provided by the software designer. Utilizing the active memory operation, we can replace multiple transactions of memory accesses over the on-chip network and related local processing element computation with a smaller number of high-level transactions and near-memory computation. We implemented a processor called active memory processor which is located near the memory and executes the active memory operations. In our case studies, we applied the concept to three real-world applications (parallelized JPEG, FFT, and text indexing for data mining) running on a 36-tile architecture with 32 cores and 4 memories and found that the programmable transaction approach can improve performace by 34.3% to 618% at the cost of additional design effort.