Eecache: Exploiting Design Choices In Energy-Efficient Last-Level Caches For Chip Multiprocessors

Power management for large last-level caches (LLCs) is important in chip-multiprocessors (CMPs), as the leakage power of LLCs accounts for a significant fraction of the limited on-chip power budget. Since not all workloads need the entire cache, portions of a shared LLC can be disabled to save energy. In this paper, we explore different design choices, from circuit-level cache organization to micro-architectural management policies, to propose a low overhead run-time mechanism for energy reduction in the shared LLC. Results show that our design (EECache) provides 14.1% energy saving at only 1.2% performance degradation on average, with negligible hardware overhead.