Heterogeneous multi-channel: Fine-grained DRAM control for both system performance and power efficiency

We propose a novel architecture of memory controller, called HMC (Heterogeneous Multi-Channel), as an improvement to the previous homogeneous multi-channel memory controller. HMC groups physical DRAM devices into logical sub-ranks with different data bus width, and controls them simultaneously. Employing new proposed memory access algorithm, HMC manages the number of devices involved in a single memory access flexibly, and achieves the best performance/power efficiency. Using four-core multiprogramming workloads, our experimental results show that HMC improves system performance by 27.6% with 24.2% reduction in DRAM power consumption on average.