Space Oblivious Compression: Power Reduction for Non-Volatile Main Memories

Abstract

Power consumption of main memory has become a critical concern and has led to proposals to employ emerging non-volatile memories (NVMs) to replace or augment DRAM. This paper proposes Space Oblivious COmpression (SOCO), an in-place lightweight compression mechanism particularly designed for reducing NVM-based main-memory energy rather than saving space. SOCO can significantly reduce the number of bits written to save considerable energy for NVM-based main memories. By relaxing the goal of a conventional compression, the proposed approach practically eliminates memory addressing and management overheads incurred by compression techniques designed to save space. Our experiments show that SOCO provides more than 50% reduction in bits written, resulting in 23% and 34% energy savings for Spin-transfer Torque (STT)-MRAM and Phase Change Memory (PCM), respectively.