Exploring Non-Volatile Main Memory Architectures for Handheld Devices

As additional functionality is being added to contemporary handheld devices, the SoCs inside these devices are becoming increasingly complex. Similarly, the applications executing on these handhelds are beginning to exhibit an ever increasing memory footprint. To support these trends, main memory capacity of these SoCs has been increasing over time. Due to these developments, memory system's contribution to the overall system power has increased dramatically. Non-volatile memories have been used in server architectures to increase capacity as well as keep memory system's power consumption in check. However, in the handheld domain, where user experience and battery life are of paramount importance, the applicability of such technologies has not been widely studied. In this paper, we propose and evaluate a number of hybrid memory architectures using mobile DRAM and PCM. We show that intelligent memory architectures, cognizant of workload's memory access patterns can provide significant energy savings without compromising on user experience. Using proposed approach, we can devise architectures that exhibit significant energy savings with only a 2.8% performance loss.