Asymmetric DRAM synthesis for heterogeneous chip multiprocessors in 3D-stacked architecture

Various computational requirements of real-world applications have leveraged moving to heterogeneous chip multiprocessors (CMPs) from homogeneous ones. In the meantime, three-dimensional integration of DRAMs and processors using Through Silicon Vias (TSVs) has emerged as the most viable solution for breaking the memory wall in CMP environment by bringing much higher memory bandwidth compared to current PCB level processor-DRAM integration. However, most researches on 3D-stacked DRAM have focused on increasing the memory bandwidth to improve the overall throughput of a system, even though the memory access requirements of real-world applications are various just as the computational requirements. To tackle this problem, we propose an asymmetric 3D-stacked DRAM architecture where the DRAM die is divided into multiple segments and the segments are optimized for different memory requirements. Also, since the optimal architecture of the DRAM can be different for different heterogeneous CMPs, we propose an automatic synthesis method for the asymmetric 3D-stacked DRAM architecture. The experimental results show that the area-power-product is reduced by 65.1% on average compared to the conventional architectures for the four realistic benchmarks and many of their derivatives.