AIM: Energy-Efficient Aggregation Inside the Memory Hierarchy

In this article, we propose Aggregation-in-Memory (AIM), a new processing-in-memory system designed for energy efficiency and near-term adoption. In order to efficiently perform aggregation, we implement simple aggregation operations in main memory and develop a locality-adaptive host architecture for in-memory aggregation, called cache-conscious aggregation. Through this, AIM executes aggregation at the most energy-efficient location among all levels of the memory hierarchy. Moreover, AIM minimally changes existing sequential programming models and provides fully automated compiler toolchain, thereby allowing unmodified legacy software to use AIM. Evaluations show that AIM greatly improves the energy efficiency of main memory and the system performance.