HalfDRAM: A High-bandwidth and Low-power DRAM Architecture from the Rethinking of Fine-grained Activation

DRAM memory is a major contributor for the total power consumption in modern computing systems. Consequently, power reduction for DRAM memory is critical to improve system-level power efficiency. Fine-grained DRAM archi-tecture [1, 2] has been proposed to reduce the activa-tion/precharge power. However, those prior work either incurs significant performance degradation or introduces large area overhead. In this paper, we propose a novel memory architec-ture Half-DRAM, in which the DRAM array is reorganized to enable only half of a row being activated. The half-row activation can effectively reduce activation power and mean-while sustain the full bandwidth one bank can provide. In addition, the half-row activation in Half-DRAM relaxes the power constraint in DRAM, and opens up opportunities for fur-ther performance gain. Furthermore, two half-row accesses can be issued in parallel by integrating the sub-array level parallelism to improve the memory level parallelism. The experimental results show that Half-DRAM can achieve both significant performance improvement and power reduction, with negligible design overhead. 1