rPRAM: Exploring Redundancy Techniques to Improve Lifetime of PCM-based Main Memory

Future main memory systems will confront the scaling challenges posed by DRAM technology and should adapt themselves to use the emerging memory technologies like Phase Change Memory (PCM, or PRAM). PCM offers advantages such as storage density, non-volatility, and lower energy consumption. However, they are constrained by limited write endurance and reduced performance. In this paper, we propose a novel PCM-based main memory system, rPRAM, that explores advanced redundancy techniques to resuscitate faulty PCM pages and reuse these pages to store data. Our preliminary experiments show that rPRAM has the potential to extend the lifetime of PCM based memory commensurate with the existing schemes like ECP, while incurring only a negligible fraction of hardware cost compared to ECP.